diff --git a/includes/abilities-api.php b/includes/abilities-api.php
index 05e4bb3..73ba658 100644
--- a/includes/abilities-api.php
+++ b/includes/abilities-api.php
@@ -254,9 +254,16 @@
  *     @type array<string, mixed> $meta                {
  *         Optional. Additional metadata for the ability.
  *
- *         @type array<string, bool|null> $annotations  Optional. Annotation metadata for the ability. Provides
- *                                                      additional semantic information about the ability's
- *                                                      characteristics and behavior.
+ *         @type array<string, bool|null> $annotations  {
+ *             Optional. Semantic annotations describing the ability's behavioral characteristics.
+ *             These annotations are hints for tooling and documentation.
+ *
+ *             @type bool|null $readonly    Optional. If true, the ability does not modify its environment.
+ *             @type bool|null $destructive Optional. If true, the ability may perform destructive updates to its environment.
+ *                                          If false, the ability performs only additive updates.
+ *             @type bool|null $idempotent  Optional. If true, calling the ability repeatedly with the same arguments
+ *                                          will have no additional effect on its environment.
+ *         }
  *         @type bool                     $show_in_rest Optional. Whether to expose this ability in the REST API.
  *                                                      When true, the ability can be invoked via HTTP requests.
  *                                                      Default false.
@@ -269,7 +276,7 @@
  * @return WP_Ability|null The registered ability instance on success, `null` on failure.
  */
 function wp_register_ability( string $name, array $args ): ?WP_Ability {
-	if ( ! did_action( 'wp_abilities_api_init' ) ) {
+	if ( ! doing_action( 'wp_abilities_api_init' ) ) {
 		_doing_it_wrong(
 			__FUNCTION__,
 			sprintf(
@@ -458,7 +465,7 @@ function wp_get_abilities(): array {
  * @return WP_Ability_Category|null The registered ability category instance on success, `null` on failure.
  */
 function wp_register_ability_category( string $slug, array $args ): ?WP_Ability_Category {
-	if ( ! did_action( 'wp_abilities_api_categories_init' ) ) {
+	if ( ! doing_action( 'wp_abilities_api_categories_init' ) ) {
 		_doing_it_wrong(
 			__FUNCTION__,
 			sprintf(
diff --git a/includes/abilities-api/class-wp-abilities-registry.php b/includes/abilities-api/class-wp-abilities-registry.php
index 398d28c..ecd6dc2 100644
--- a/includes/abilities-api/class-wp-abilities-registry.php
+++ b/includes/abilities-api/class-wp-abilities-registry.php
@@ -61,7 +61,16 @@ final class WP_Abilities_Registry {
 	 *     @type array<string, mixed> $meta                  {
 	 *         Optional. Additional metadata for the ability.
 	 *
-	 *         @type array<string, null|bool> $annotations  Optional. Annotation metadata for the ability.
+	 *         @type array<string, bool|null> $annotations  {
+	 *             Optional. Semantic annotations describing the ability's behavioral characteristics.
+	 *             These annotations are hints for tooling and documentation.
+	 *
+	 *             @type bool|null $readonly    Optional. If true, the ability does not modify its environment.
+	 *             @type bool|null $destructive Optional. If true, the ability may perform destructive updates to its environment.
+	 *                                          If false, the ability performs only additive updates.
+	 *             @type bool|null $idempotent  Optional. If true, calling the ability repeatedly with the same arguments
+	 *                                          will have no additional effect on its environment.
+	 *         }
 	 *         @type bool                     $show_in_rest Optional. Whether to expose this ability in the REST API. Default false.
 	 *     }
 	 *     @type string               $ability_class         Optional. Custom class to instantiate instead of WP_Ability.
diff --git a/includes/abilities-api/class-wp-ability-categories-registry.php b/includes/abilities-api/class-wp-ability-categories-registry.php
index 00e6ad8..58bc432 100644
--- a/includes/abilities-api/class-wp-ability-categories-registry.php
+++ b/includes/abilities-api/class-wp-ability-categories-registry.php
@@ -206,7 +206,7 @@ public static function get_instance(): ?self {
 				__METHOD__,
 				sprintf(
 					// translators: %s: init action.
-					__( 'Ability API should not be initialized before the %s action has fired' ),
+					__( 'Ability API should not be initialized before the %s action has fired.' ),
 					'<code>init</code>'
 				),
 				'6.9.0'
diff --git a/includes/abilities-api/class-wp-ability.php b/includes/abilities-api/class-wp-ability.php
index b890d92..d116080 100644
--- a/includes/abilities-api/class-wp-ability.php
+++ b/includes/abilities-api/class-wp-ability.php
@@ -33,7 +33,7 @@ class WP_Ability {
 	 * They are not guaranteed to provide a faithful description of ability behavior.
 	 *
 	 * @since 6.9.0
-	 * @var array<string, (bool|null)>
+	 * @var array<string, bool|null>
 	 */
 	protected static $default_annotations = array(
 		// If true, the ability does not modify its environment.
@@ -150,7 +150,16 @@ class WP_Ability {
 	 *     @type array<string, mixed> $meta                  {
 	 *         Optional. Additional metadata for the ability.
 	 *
-	 *         @type array<string, null|bool> $annotations  Optional. Annotation metadata for the ability.
+	 *         @type array<string, bool|null> $annotations  {
+	 *             Optional. Semantic annotations describing the ability's behavioral characteristics.
+	 *             These annotations are hints for tooling and documentation.
+	 *
+	 *             @type bool|null $readonly    Optional. If true, the ability does not modify its environment.
+	 *             @type bool|null $destructive Optional. If true, the ability may perform destructive updates to its environment.
+	 *                                          If false, the ability performs only additive updates.
+	 *             @type bool|null $idempotent  Optional. If true, calling the ability repeatedly with the same arguments
+	 *                                          will have no additional effect on its environment.
+	 *         }
 	 *         @type bool                     $show_in_rest Optional. Whether to expose this ability in the REST API. Default false.
 	 *     }
 	 * }
@@ -205,7 +214,16 @@ public function __construct( string $name, array $args ) {
 	 *     @type array<string, mixed> $meta                  {
 	 *         Optional. Additional metadata for the ability.
 	 *
-	 *         @type array<string, null|bool> $annotations  Optional. Annotation metadata for the ability.
+	 *         @type array<string, bool|null> $annotations  {
+	 *             Optional. Semantic annotations describing the ability's behavioral characteristics.
+	 *             These annotations are hints for tooling and documentation.
+	 *
+	 *             @type bool|null $readonly    Optional. If true, the ability does not modify its environment.
+	 *             @type bool|null $destructive Optional. If true, the ability may perform destructive updates to its environment.
+	 *                                          If false, the ability performs only additive updates.
+	 *             @type bool|null $idempotent  Optional. If true, calling the ability repeatedly with the same arguments
+	 *                                          will have no additional effect on its environment.
+	 *         }
 	 *         @type bool                     $show_in_rest Optional. Whether to expose this ability in the REST API. Default false.
 	 *     }
 	 * }
@@ -224,7 +242,16 @@ public function __construct( string $name, array $args ) {
 	 *     @type array<string, mixed> $meta                  {
 	 *         Additional metadata for the ability.
 	 *
-	 *         @type array<string, null|bool> $annotations  Optional. Annotation metadata for the ability.
+	 *         @type array<string, bool|null> $annotations  {
+	 *             Semantic annotations describing the ability's behavioral characteristics.
+	 *             These annotations are hints for tooling and documentation.
+	 *
+	 *             @type bool|null $readonly    If true, the ability does not modify its environment.
+	 *             @type bool|null $destructive If true, the ability may perform destructive updates to its environment.
+	 *                                          If false, the ability performs only additive updates.
+	 *             @type bool|null $idempotent  If true, calling the ability repeatedly with the same arguments
+	 *                                          will have no additional effect on its environment.
+	 *         }
 	 *         @type bool                     $show_in_rest Whether to expose this ability in the REST API. Default false.
 	 *     }
 	 * }
@@ -498,6 +525,14 @@ protected function invoke_callback( callable $callback, $input = null ) {
 	 * @return bool|WP_Error Whether the ability has the necessary permission.
 	 */
 	public function check_permissions( $input = null ) {
+		if ( ! is_callable( $this->permission_callback ) ) {
+			return new WP_Error(
+				'ability_invalid_permission_callback',
+				/* translators: %s ability name. */
+				sprintf( __( 'Ability "%s" does not have a valid permission callback.' ), esc_html( $this->name ) )
+			);
+		}
+
 		return $this->invoke_callback( $this->permission_callback, $input );
 	}
 
diff --git a/tests/unit/abilities-api/wpAbilitiesRegistry.php b/tests/unit/abilities-api/wpAbilitiesRegistry.php
index 95fa29a..badd81c 100644
--- a/tests/unit/abilities-api/wpAbilitiesRegistry.php
+++ b/tests/unit/abilities-api/wpAbilitiesRegistry.php
@@ -29,8 +29,9 @@ public function set_up(): void {
 
 		remove_all_filters( 'wp_register_ability_args' );
 
-		// Fire the init hook to allow test ability category registration.
-		do_action( 'wp_abilities_api_categories_init' );
+		// Simulates the Abilities API init hook to allow test ability category registration.
+		global $wp_current_filter;
+		$wp_current_filter[] = 'wp_abilities_api_categories_init';
 		wp_register_ability_category(
 			'math',
 			array(
@@ -38,6 +39,7 @@ public function set_up(): void {
 				'description' => 'Mathematical operations and calculations.',
 			)
 		);
+		array_pop( $wp_current_filter );
 
 		self::$test_ability_args = array(
 			'label'               => 'Add numbers',
diff --git a/tests/unit/abilities-api/wpAbility.php b/tests/unit/abilities-api/wpAbility.php
index 910ae7d..73a5fbf 100644
--- a/tests/unit/abilities-api/wpAbility.php
+++ b/tests/unit/abilities-api/wpAbility.php
@@ -18,16 +18,6 @@ class Tests_Abilities_API_WpAbility extends WP_UnitTestCase {
 	public function set_up(): void {
 		parent::set_up();
 
-		// Fire the init hook to allow test ability category registration.
-		do_action( 'wp_abilities_api_categories_init' );
-		wp_register_ability_category(
-			'math',
-			array(
-				'label'       => 'Math',
-				'description' => 'Mathematical operations and calculations.',
-			)
-		);
-
 		self::$test_ability_properties = array(
 			'label'               => 'Calculator',
 			'description'         => 'Calculates the result of math operations.',
@@ -56,9 +46,6 @@ public function set_up(): void {
 	 * Tear down after each test.
 	 */
 	public function tear_down(): void {
-		// Clean up registered test ability category.
-		wp_unregister_ability_category( 'math' );
-
 		parent::tear_down();
 	}
 
diff --git a/tests/unit/abilities-api/wpCoreAbilities.php b/tests/unit/abilities-api/wpCoreAbilities.php
deleted file mode 100644
index d69dc24..0000000
--- a/tests/unit/abilities-api/wpCoreAbilities.php
+++ /dev/null
@@ -1,180 +0,0 @@
-<?php declare( strict_types=1 );
-
-/**
- * Tests for the core abilities shipped with the Abilities API.
- *
- * @group abilities-api
- */
-class Tests_Abilities_API_WpCoreAbilities extends WP_UnitTestCase {
-
-	/**
-	 * Sets up the test.
-	 */
-	public function set_up(): void {
-		parent::set_up();
-
-        // Unregister core abilities if they were already registered to avoid duplicate registration warnings.
-        $registry = WP_Abilities_Registry::get_instance();
-        if ( $registry->is_registered( 'core/get-site-info' ) ) {
-            $registry->unregister( 'core/get-site-info' );
-        }
-        if ( $registry->is_registered( 'core/get-user-info' ) ) {
-            $registry->unregister( 'core/get-user-info' );
-        }
-        if ( $registry->is_registered( 'core/get-environment-info' ) ) {
-            $registry->unregister( 'core/get-environment-info' );
-        }
-
-        // Unregister categories if they exist.
-        $category_registry = WP_Ability_Categories_Registry::get_instance();
-        if ( $category_registry->is_registered( 'site' ) ) {
-            wp_unregister_ability_category( 'site' );
-        }
-        if ( $category_registry->is_registered( 'user' ) ) {
-            wp_unregister_ability_category( 'user' );
-        }
-
-		// Register core abilities category during the proper hook.
-		$callback = static function (): void {
-			wp_register_core_ability_categories();
-		};
-		add_action( 'wp_abilities_api_categories_init', $callback );
-		do_action( 'wp_abilities_api_categories_init', WP_Ability_Categories_Registry::get_instance() );
-		remove_action( 'wp_abilities_api_categories_init', $callback );
-
-		// Fire the init action if it hasn't been fired yet.
-		if ( ! did_action( 'wp_abilities_api_init' ) ) {
-			do_action( 'wp_abilities_api_init' );
-		}
-
-		// Register core abilities for testing.
-		wp_register_core_abilities();
-	}
-
-	/**
-     * Tests that the `core/get-site-info` ability is registered with the expected schema.
-     */
-    public function test_core_get_bloginfo_ability_is_registered(): void {
-        $ability = wp_get_ability( 'core/get-site-info' );
-
-		$this->assertInstanceOf( WP_Ability::class, $ability );
-		$this->assertTrue( $ability->get_meta_item( 'show_in_rest', false ) );
-
-		$input_schema  = $ability->get_input_schema();
-		$output_schema = $ability->get_output_schema();
-
-		$this->assertSame( 'object', $input_schema['type'] );
-		$this->assertArrayHasKey( 'default', $input_schema );
-		$this->assertSame( array(), $input_schema['default'] );
-
-		// Input schema should have optional fields array.
-		$this->assertArrayHasKey( 'fields', $input_schema['properties'] );
-		$this->assertSame( 'array', $input_schema['properties']['fields']['type'] );
-		$this->assertContains( 'name', $input_schema['properties']['fields']['items']['enum'] );
-
-		// Output schema should have all fields documented.
-		$this->assertArrayHasKey( 'name', $output_schema['properties'] );
-		$this->assertArrayHasKey( 'url', $output_schema['properties'] );
-		$this->assertArrayHasKey( 'version', $output_schema['properties'] );
-	}
-
-	/**
-     * Tests executing the `core/get-site-info` ability returns all fields by default.
-     */
-    public function test_core_get_bloginfo_executes(): void {
-        // Requires manage_options.
-        $admin_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
-        wp_set_current_user( $admin_id );
-
-        $ability = wp_get_ability( 'core/get-site-info' );
-
-		// Test without fields parameter - should return all fields.
-		$result = $ability->execute();
-
-		$this->assertIsArray( $result );
-		$this->assertArrayHasKey( 'name', $result );
-		$this->assertArrayHasKey( 'description', $result );
-		$this->assertArrayHasKey( 'url', $result );
-		$this->assertArrayHasKey( 'version', $result );
-		$this->assertSame( get_bloginfo( 'name' ), $result['name'] );
-
-		// Test with fields parameter - should return only requested fields.
-		$result = $ability->execute(
-			array(
-				'fields' => array( 'name', 'url' ),
-			)
-		);
-
-		$this->assertIsArray( $result );
-		$this->assertArrayHasKey( 'name', $result );
-		$this->assertArrayHasKey( 'url', $result );
-		$this->assertArrayNotHasKey( 'description', $result );
-		$this->assertArrayNotHasKey( 'version', $result );
-		$this->assertSame( get_bloginfo( 'name' ), $result['name'] );
-		$this->assertSame( get_bloginfo( 'url' ), $result['url'] );
-
-        wp_set_current_user( 0 );
-    }
-
-	/**
-     * Tests that executing the current user info ability requires authentication.
-     */
-    public function test_core_get_current_user_info_requires_authentication(): void {
-        $ability = wp_get_ability( 'core/get-user-info' );
-
-		$this->assertFalse( $ability->check_permissions() );
-
-		$result = $ability->execute();
-		$this->assertWPError( $result );
-		$this->assertSame( 'ability_invalid_permissions', $result->get_error_code() );
-	}
-
-	/**
-     * Tests executing the current user info ability as an authenticated user.
-     */
-    public function test_core_get_current_user_info_returns_user_data(): void {
-		$user_id = self::factory()->user->create(
-			array(
-				'role'   => 'subscriber',
-				'locale' => 'fr_FR',
-			)
-		);
-
-		wp_set_current_user( $user_id );
-
-        $ability = wp_get_ability( 'core/get-user-info' );
-
-		$this->assertTrue( $ability->check_permissions() );
-
-		$result = $ability->execute();
-		$this->assertSame( $user_id, $result['id'] );
-		$this->assertSame( 'fr_FR', $result['locale'] );
-		$this->assertSame( 'subscriber', $result['roles'][0] );
-		$this->assertSame( get_userdata( $user_id )->display_name, $result['display_name'] );
-
-		wp_set_current_user( 0 );
-	}
-
-	/**
-     * Tests executing the environment info ability.
-     */
-    public function test_core_get_environment_type_executes(): void {
-        // Requires manage_options.
-        $admin_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
-        wp_set_current_user( $admin_id );
-
-        $ability      = wp_get_ability( 'core/get-environment-info' );
-        $environment  = wp_get_environment_type();
-        $ability_data = $ability->execute();
-
-        $this->assertIsArray( $ability_data );
-        $this->assertArrayHasKey( 'environment', $ability_data );
-        $this->assertArrayHasKey( 'php_version', $ability_data );
-        $this->assertArrayHasKey( 'db_server_info', $ability_data );
-        $this->assertArrayHasKey( 'wp_version', $ability_data );
-        $this->assertSame( $environment, $ability_data['environment'] );
-
-        wp_set_current_user( 0 );
-    }
-
-}
diff --git a/tests/unit/abilities-api/wpRegisterAbility.php b/tests/unit/abilities-api/wpRegisterAbility.php
index 21b108f..91a8aaf 100644
--- a/tests/unit/abilities-api/wpRegisterAbility.php
+++ b/tests/unit/abilities-api/wpRegisterAbility.php
@@ -29,10 +29,12 @@ class Test_Abilities_API_WpRegisterAbility extends WP_UnitTestCase {
 	 * Set up before each test.
 	 */
 	public function set_up(): void {
+		global $wp_current_filter;
+
 		parent::set_up();
 
-		// Fire the init hook to allow test ability category registration.
-		do_action( 'wp_abilities_api_categories_init' );
+		// Simulate the init hook for ability categories to allow test ability category registration.
+		$wp_current_filter[] = 'wp_abilities_api_categories_init';
 		wp_register_ability_category(
 			'math',
 			array(
@@ -86,6 +88,8 @@ public function set_up(): void {
 	 * Tear down after each test.
 	 */
 	public function tear_down(): void {
+		global $wp_current_filter;
+
 		foreach ( wp_get_abilities() as $ability ) {
 			if ( ! str_starts_with( $ability->get_name(), 'test/' ) ) {
 				continue;
@@ -100,6 +104,15 @@ public function tear_down(): void {
 		parent::tear_down();
 	}
 
+	/**
+	 * Simulates the `wp_abilities_api_init` action.
+	 */
+	private function simulate_doing_wp_abilities_init_action() {
+		global $wp_current_filter;
+
+		$wp_current_filter[] = 'wp_abilities_api_init';
+	}
+
 	/**
 	 * Tests registering an ability with invalid name.
 	 *
@@ -108,7 +121,7 @@ public function tear_down(): void {
 	 * @expectedIncorrectUsage WP_Abilities_Registry::register
 	 */
 	public function test_register_ability_invalid_name(): void {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		$result = wp_register_ability( 'invalid_name', array() );
 
@@ -116,28 +129,17 @@ public function test_register_ability_invalid_name(): void {
 	}
 
 	/**
-	 * Tests registering an ability when `abilities_api_init` action has not fired.
+	 * Tests registering an ability when `wp_abilities_api_init` action has not fired.
 	 *
 	 * @ticket 64098
 	 *
 	 * @expectedIncorrectUsage wp_register_ability
 	 */
 	public function test_register_ability_no_abilities_api_init_action(): void {
-		global $wp_actions;
-
-		// Store the original action count.
-		$original_count = isset( $wp_actions['wp_abilities_api_init'] ) ? $wp_actions['wp_abilities_api_init'] : 0;
-
-		// Reset the action count to simulate it not being fired.
-		unset( $wp_actions['wp_abilities_api_init'] );
+		$this->assertFalse( doing_action( 'wp_abilities_api_init' ) );
 
 		$result = wp_register_ability( self::$test_ability_name, self::$test_ability_args );
 
-		// Restore the original action count.
-		if ( $original_count > 0 ) {
-			$wp_actions['wp_abilities_api_init'] = $original_count;
-		}
-
 		$this->assertNull( $result );
 	}
 
@@ -151,14 +153,14 @@ public function test_register_ability_no_abilities_api_init_action(): void {
 	public function test_register_ability_no_init_action(): void {
 		global $wp_actions;
 
-		do_action( 'wp_abilities_api_init' );
-
 		// Store the original action count.
 		$original_count = isset( $wp_actions['init'] ) ? $wp_actions['init'] : 0;
 
 		// Reset the action count to simulate it not being fired.
 		unset( $wp_actions['init'] );
 
+		$this->simulate_doing_wp_abilities_init_action();
+
 		$result = wp_register_ability( self::$test_ability_name, self::$test_ability_args );
 
 		// Restore the original action count.
@@ -175,7 +177,7 @@ public function test_register_ability_no_init_action(): void {
 	 * @ticket 64098
 	 */
 	public function test_register_valid_ability(): void {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		$result = wp_register_ability( self::$test_ability_name, self::$test_ability_args );
 
@@ -225,7 +227,7 @@ public function test_register_valid_ability(): void {
 	 * @ticket 64098
 	 */
 	public function test_register_ability_no_permissions(): void {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		self::$test_ability_args['permission_callback'] = static function (): bool {
 			return false;
@@ -260,7 +262,7 @@ public function test_register_ability_no_permissions(): void {
 	 * @ticket 64098
 	 */
 	public function test_register_ability_custom_ability_class(): void {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		$result = wp_register_ability(
 			self::$test_ability_name,
@@ -302,7 +304,7 @@ public function test_register_ability_custom_ability_class(): void {
 	 * @ticket 64098
 	 */
 	public function test_execute_ability_no_input_schema_match(): void {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		$result = wp_register_ability( self::$test_ability_name, self::$test_ability_args );
 
@@ -331,7 +333,7 @@ public function test_execute_ability_no_input_schema_match(): void {
 	 * @ticket 64098
 	 */
 	public function test_execute_ability_no_output_schema_match(): void {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		self::$test_ability_args['execute_callback'] = static function (): bool {
 			return true;
@@ -362,7 +364,7 @@ public function test_execute_ability_no_output_schema_match(): void {
 	 * @ticket 64098
 	 */
 	public function test_validate_input_no_input_schema_match(): void {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		$result = wp_register_ability( self::$test_ability_name, self::$test_ability_args );
 
@@ -391,7 +393,7 @@ public function test_validate_input_no_input_schema_match(): void {
 	 * @ticket 64098
 	 */
 	public function test_permission_callback_receives_input(): void {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		$received_input                                 = null;
 		self::$test_ability_args['permission_callback'] = static function ( array $input ) use ( &$received_input ): bool {
@@ -453,6 +455,8 @@ public function test_unregister_ability_no_init_action(): void {
 		// Reset the action count to simulate it not being fired.
 		unset( $wp_actions['init'] );
 
+		$this->simulate_doing_wp_abilities_init_action();
+
 		$result = wp_unregister_ability( self::$test_ability_name );
 
 		// Restore the original action count.
@@ -469,7 +473,7 @@ public function test_unregister_ability_no_init_action(): void {
 	 * @ticket 64098
 	 */
 	public function test_unregister_existing_ability() {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		wp_register_ability( self::$test_ability_name, self::$test_ability_args );
 
@@ -497,6 +501,8 @@ public function test_get_ability_no_init_action(): void {
 		// Reset the action count to simulate it not being fired.
 		unset( $wp_actions['init'] );
 
+		$this->simulate_doing_wp_abilities_init_action();
+
 		$result = wp_get_ability( self::$test_ability_name );
 
 		// Restore the original action count.
@@ -513,6 +519,8 @@ public function test_get_ability_no_init_action(): void {
 	 * @ticket 64098
 	 */
 	public function test_get_existing_ability_using_callback() {
+		$this->simulate_doing_wp_abilities_init_action();
+
 		$name     = self::$test_ability_name;
 		$args     = self::$test_ability_args;
 		$callback = static function ( $instance ) use ( $name, $args ) {
@@ -556,6 +564,8 @@ public function test_has_ability_no_init_action(): void {
 		// Reset the action count to simulate it not being fired.
 		unset( $wp_actions['init'] );
 
+		$this->simulate_doing_wp_abilities_init_action();
+
 		$result = wp_has_ability( self::$test_ability_name );
 
 		// Restore the original action count.
@@ -572,7 +582,7 @@ public function test_has_ability_no_init_action(): void {
 	 * @ticket 64098
 	 */
 	public function test_has_registered_ability() {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		wp_register_ability( self::$test_ability_name, self::$test_ability_args );
 
@@ -587,7 +597,7 @@ public function test_has_registered_ability() {
 	 * @ticket 64098
 	 */
 	public function test_has_registered_nonexistent_ability() {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		$result = wp_has_ability( 'test/non-existent' );
 
@@ -610,6 +620,8 @@ public function test_get_abilities_no_init_action(): void {
 		// Reset the action count to simulate it not being fired.
 		unset( $wp_actions['init'] );
 
+		$this->simulate_doing_wp_abilities_init_action();
+
 		$result = wp_get_abilities();
 
 		// Restore the original action count.
@@ -626,7 +638,7 @@ public function test_get_abilities_no_init_action(): void {
 	 * @ticket 64098
 	 */
 	public function test_get_all_registered_abilities() {
-		do_action( 'wp_abilities_api_init' );
+		$this->simulate_doing_wp_abilities_init_action();
 
 		$ability_one_name = 'test/ability-one';
 		$ability_one_args = self::$test_ability_args;
diff --git a/tests/unit/abilities-api/wpRegisterAbilityCategory.php b/tests/unit/abilities-api/wpRegisterAbilityCategory.php
index ede55f9..169ea28 100644
--- a/tests/unit/abilities-api/wpRegisterAbilityCategory.php
+++ b/tests/unit/abilities-api/wpRegisterAbilityCategory.php
@@ -45,13 +45,24 @@ public function tear_down(): void {
 	}
 
 	/**
-	 * Test registering ability category before `abilities_api_categories_init` hook.
+	 * Simulates the `wp_abilities_api_categories_init` action.
+	 */
+	private function simulate_doing_wp_ability_categories_init_action() {
+		global $wp_current_filter;
+
+		$wp_current_filter[] = 'wp_abilities_api_categories_init';
+	}
+
+	/**
+	 * Test registering ability category before `wp_abilities_api_categories_init` hook.
 	 *
 	 * @ticket 64098
 	 *
 	 * @expectedIncorrectUsage wp_register_ability_category
 	 */
 	public function test_register_category_before_init_hook(): void {
+		$this->assertFalse( doing_action( 'wp_abilities_api_categories_init' ) );
+
 		$result = wp_register_ability_category(
 			self::$test_ability_category_name,
 			self::$test_ability_category_args
@@ -70,14 +81,14 @@ public function test_register_category_before_init_hook(): void {
 	public function test_register_ability_category_no_init_action(): void {
 		global $wp_actions;
 
-		do_action( 'wp_abilities_api_categories_init' );
-
 		// Store the original action count.
 		$original_count = isset( $wp_actions['init'] ) ? $wp_actions['init'] : 0;
 
 		// Reset the action count to simulate it not being fired.
 		unset( $wp_actions['init'] );
 
+		$this->simulate_doing_wp_ability_categories_init_action();
+
 		$result = wp_register_ability_category(
 			self::$test_ability_category_name,
 			self::$test_ability_category_args
@@ -97,7 +108,7 @@ public function test_register_ability_category_no_init_action(): void {
 	 * @ticket 64098
 	 */
 	public function test_register_valid_category(): void {
-		do_action( 'wp_abilities_api_categories_init' );
+		$this->simulate_doing_wp_ability_categories_init_action();
 
 		$result = wp_register_ability_category(
 			self::$test_ability_category_name,
@@ -120,14 +131,14 @@ public function test_register_valid_category(): void {
 	public function test_unregister_ability_category_no_init_action(): void {
 		global $wp_actions;
 
-		do_action( 'wp_abilities_api_categories_init' );
-
 		// Store the original action count.
 		$original_count = isset( $wp_actions['init'] ) ? $wp_actions['init'] : 0;
 
 		// Reset the action count to simulate it not being fired.
 		unset( $wp_actions['init'] );
 
+		$this->simulate_doing_wp_ability_categories_init_action();
+
 		$result = wp_unregister_ability_category( self::$test_ability_category_name );
 
 		// Restore the original action count.
@@ -146,7 +157,7 @@ public function test_unregister_ability_category_no_init_action(): void {
 	 * @expectedIncorrectUsage WP_Ability_Categories_Registry::unregister
 	 */
 	public function test_unregister_nonexistent_category(): void {
-		do_action( 'wp_abilities_api_categories_init' );
+		$this->simulate_doing_wp_ability_categories_init_action();
 
 		$result = wp_unregister_ability_category( 'test-nonexistent' );
 
@@ -159,7 +170,7 @@ public function test_unregister_nonexistent_category(): void {
 	 * @ticket 64098
 	 */
 	public function test_unregister_existing_category(): void {
-		do_action( 'wp_abilities_api_categories_init' );
+		$this->simulate_doing_wp_ability_categories_init_action();
 
 		wp_register_ability_category(
 			self::$test_ability_category_name,
@@ -182,14 +193,14 @@ public function test_unregister_existing_category(): void {
 	public function test_has_ability_category_no_init_action(): void {
 		global $wp_actions;
 
-		do_action( 'wp_abilities_api_categories_init' );
-
 		// Store the original action count.
 		$original_count = isset( $wp_actions['init'] ) ? $wp_actions['init'] : 0;
 
 		// Reset the action count to simulate it not being fired.
 		unset( $wp_actions['init'] );
 
+		$this->simulate_doing_wp_ability_categories_init_action();
+
 		$result = wp_has_ability_category( self::$test_ability_category_name );
 
 		// Restore the original action count.
@@ -206,7 +217,7 @@ public function test_has_ability_category_no_init_action(): void {
 	 * @ticket 64098
 	 */
 	public function test_has_registered_nonexistent_ability_category(): void {
-		do_action( 'wp_abilities_api_categories_init' );
+		$this->simulate_doing_wp_ability_categories_init_action();
 
 		$result = wp_has_ability_category( 'test/non-existent' );
 
@@ -219,7 +230,7 @@ public function test_has_registered_nonexistent_ability_category(): void {
 	 * @ticket 64098
 	 */
 	public function test_has_registered_ability_category(): void {
-		do_action( 'wp_abilities_api_categories_init' );
+		$this->simulate_doing_wp_ability_categories_init_action();
 
 		$category_slug = self::$test_ability_category_name;
 
@@ -243,14 +254,14 @@ public function test_has_registered_ability_category(): void {
 	public function test_get_ability_category_no_init_action(): void {
 		global $wp_actions;
 
-		do_action( 'wp_abilities_api_categories_init' );
-
 		// Store the original action count.
 		$original_count = isset( $wp_actions['init'] ) ? $wp_actions['init'] : 0;
 
 		// Reset the action count to simulate it not being fired.
 		unset( $wp_actions['init'] );
 
+		$this->simulate_doing_wp_ability_categories_init_action();
+
 		$result = wp_get_ability_category( self::$test_ability_category_name );
 
 		// Restore the original action count.
@@ -269,7 +280,7 @@ public function test_get_ability_category_no_init_action(): void {
 	 * @expectedIncorrectUsage WP_Ability_Categories_Registry::get_registered
 	 */
 	public function test_get_nonexistent_category(): void {
-		do_action( 'wp_abilities_api_categories_init' );
+		$this->simulate_doing_wp_ability_categories_init_action();
 
 		$result = wp_get_ability_category( 'test-nonexistent' );
 
@@ -316,14 +327,14 @@ public function test_get_existing_category_using_callback(): void {
 	public function test_get_ability_categories_no_init_action(): void {
 		global $wp_actions;
 
-		do_action( 'wp_abilities_api_categories_init' );
-
 		// Store the original action count.
 		$original_count = isset( $wp_actions['init'] ) ? $wp_actions['init'] : 0;
 
 		// Reset the action count to simulate it not being fired.
 		unset( $wp_actions['init'] );
 
+		$this->simulate_doing_wp_ability_categories_init_action();
+
 		$result = wp_get_ability_categories( self::$test_ability_category_name );
 
 		// Restore the original action count.
@@ -340,7 +351,7 @@ public function test_get_ability_categories_no_init_action(): void {
 	 * @ticket 64098
 	 */
 	public function test_get_all_categories(): void {
-		do_action( 'wp_abilities_api_categories_init' );
+		$this->simulate_doing_wp_ability_categories_init_action();
 
 		wp_register_ability_category(
 			self::$test_ability_category_name,
diff --git a/tests/unit/abilities-api/wpRegisterCoreAbilities.php b/tests/unit/abilities-api/wpRegisterCoreAbilities.php
new file mode 100644
index 0000000..c89d6da
--- /dev/null
+++ b/tests/unit/abilities-api/wpRegisterCoreAbilities.php
@@ -0,0 +1,177 @@
+<?php
+
+declare( strict_types=1 );
+
+/**
+ * Tests for the core abilities shipped with the Abilities API.
+ *
+ * @covers wp_register_core_ability_categories
+ * @covers wp_register_core_abilities
+ *
+ * @group abilities-api
+ */
+class Tests_Abilities_API_WpRegisterCoreAbilities extends WP_UnitTestCase {
+
+	/**
+	 * Set up before the class.
+	 *
+	 * @since 6.9.0
+	 */
+	public static function set_up_before_class(): void {
+		parent::set_up_before_class();
+
+		// Ensure core abilities are registered for these tests.
+		// Temporarily remove the unhook functions so we can register core abilities.
+		remove_action( 'wp_abilities_api_categories_init', '_unhook_core_ability_categories_registration', 1 );
+		remove_action( 'wp_abilities_api_init', '_unhook_core_abilities_registration', 1 );
+
+		// Add the core registration hooks and fire the actions.
+		add_action( 'wp_abilities_api_categories_init', 'wp_register_core_ability_categories' );
+		add_action( 'wp_abilities_api_init', 'wp_register_core_abilities' );
+		do_action( 'wp_abilities_api_categories_init' );
+		do_action( 'wp_abilities_api_init' );
+	}
+
+	/**
+	 * Tear down after the class.
+	 *
+	 * @since 6.9.0
+	 */
+	public static function tear_down_after_class(): void {
+		// Re-add the unhook functions for subsequent tests.
+		add_action( 'wp_abilities_api_categories_init', '_unhook_core_ability_categories_registration', 1 );
+		add_action( 'wp_abilities_api_init', '_unhook_core_abilities_registration', 1 );
+
+		// Remove the core abilities and their categories.
+		foreach ( wp_get_abilities() as $ability ) {
+			wp_unregister_ability( $ability->get_name() );
+		}
+		foreach ( wp_get_ability_categories() as $ability_category ) {
+			wp_unregister_ability_category( $ability_category->get_slug() );
+		}
+
+		parent::tear_down_after_class();
+	}
+
+	/**
+	 * Tests that the `core/get-site-info` ability is registered with the expected schema.
+	 * @ticket 64146
+	 */
+	public function test_core_get_site_info_ability_is_registered(): void {
+		$ability = wp_get_ability( 'core/get-site-info' );
+
+		$this->assertInstanceOf( WP_Ability::class, $ability );
+		$this->assertTrue( $ability->get_meta_item( 'show_in_rest', false ) );
+
+		$input_schema  = $ability->get_input_schema();
+		$output_schema = $ability->get_output_schema();
+
+		$this->assertSame( 'object', $input_schema['type'] );
+		$this->assertArrayHasKey( 'default', $input_schema );
+		$this->assertSame( array(), $input_schema['default'] );
+
+		// Input schema should have optional fields array.
+		$this->assertArrayHasKey( 'fields', $input_schema['properties'] );
+		$this->assertSame( 'array', $input_schema['properties']['fields']['type'] );
+		$this->assertContains( 'name', $input_schema['properties']['fields']['items']['enum'] );
+
+		// Output schema should have all fields documented.
+		$this->assertArrayHasKey( 'name', $output_schema['properties'] );
+		$this->assertArrayHasKey( 'url', $output_schema['properties'] );
+		$this->assertArrayHasKey( 'version', $output_schema['properties'] );
+	}
+
+	/**
+	 * Tests executing the `core/get-site-info` ability returns all fields by default.
+	 * @ticket 64146
+	 */
+	public function test_core_get_site_info_executes(): void {
+		// Requires manage_options.
+		$admin_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		wp_set_current_user( $admin_id );
+
+		$ability = wp_get_ability( 'core/get-site-info' );
+
+		// Test without fields parameter - should return all fields.
+		$result = $ability->execute();
+
+		$this->assertIsArray( $result );
+		$this->assertArrayHasKey( 'name', $result );
+		$this->assertArrayHasKey( 'description', $result );
+		$this->assertArrayHasKey( 'url', $result );
+		$this->assertArrayHasKey( 'version', $result );
+		$this->assertSame( get_bloginfo( 'name' ), $result['name'] );
+
+		// Test with fields parameter - should return only requested fields.
+		$result = $ability->execute(
+			array(
+				'fields' => array( 'name', 'url' ),
+			)
+		);
+
+		$this->assertIsArray( $result );
+		$this->assertCount( 2, $result );
+		$this->assertSame( get_bloginfo( 'name' ), $result['name'] );
+		$this->assertSame( get_bloginfo( 'url' ), $result['url'] );
+	}
+
+	/**
+	 * Tests that executing the current user info ability requires authentication.
+	 * @ticket 64146
+	 */
+	public function test_core_get_current_user_info_requires_authentication(): void {
+		$ability = wp_get_ability( 'core/get-user-info' );
+
+		$this->assertFalse( $ability->check_permissions() );
+
+		$result = $ability->execute();
+		$this->assertWPError( $result );
+		$this->assertSame( 'ability_invalid_permissions', $result->get_error_code() );
+	}
+
+	/**
+	 * Tests executing the current user info ability as an authenticated user.
+	 * @ticket 64146
+	 */
+	public function test_core_get_current_user_info_returns_user_data(): void {
+		$user_id = self::factory()->user->create(
+			array(
+				'role'   => 'subscriber',
+				'locale' => 'fr_FR',
+			)
+		);
+
+		wp_set_current_user( $user_id );
+
+		$ability = wp_get_ability( 'core/get-user-info' );
+
+		$this->assertTrue( $ability->check_permissions() );
+
+		$result = $ability->execute();
+		$this->assertSame( $user_id, $result['id'] );
+		$this->assertSame( 'fr_FR', $result['locale'] );
+		$this->assertSame( 'subscriber', $result['roles'][0] );
+		$this->assertSame( get_userdata( $user_id )->display_name, $result['display_name'] );
+	}
+
+	/**
+	 * Tests executing the environment info ability.
+	 * @ticket 64146
+	 */
+	public function test_core_get_environment_info_executes(): void {
+		// Requires manage_options.
+		$admin_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		wp_set_current_user( $admin_id );
+
+		$ability      = wp_get_ability( 'core/get-environment-info' );
+		$environment  = wp_get_environment_type();
+		$ability_data = $ability->execute();
+
+		$this->assertIsArray( $ability_data );
+		$this->assertArrayHasKey( 'environment', $ability_data );
+		$this->assertArrayHasKey( 'php_version', $ability_data );
+		$this->assertArrayHasKey( 'db_server_info', $ability_data );
+		$this->assertArrayHasKey( 'wp_version', $ability_data );
+		$this->assertSame( $environment, $ability_data['environment'] );
+	}
+}
diff --git a/tests/unit/rest-api/wpRestAbilitiesV1CategoriesController.php b/tests/unit/rest-api/wpRestAbilitiesV1CategoriesController.php
index a6b7f23..2fa665e 100644
--- a/tests/unit/rest-api/wpRestAbilitiesV1CategoriesController.php
+++ b/tests/unit/rest-api/wpRestAbilitiesV1CategoriesController.php
@@ -62,8 +62,6 @@ public function set_up(): void {
 
 		do_action( 'rest_api_init' );
 
-		// Initialize the API and register test ability categories.
-		do_action( 'wp_abilities_api_categories_init' );
 		$this->register_test_ability_categories();
 
 		wp_set_current_user( self::$admin_user_id );
@@ -93,6 +91,10 @@ public function tear_down(): void {
 	 * Register test ability categories for testing.
 	 */
 	public function register_test_ability_categories(): void {
+		// Simulates the init hook to allow test ability categories registration.
+		global $wp_current_filter;
+		$wp_current_filter[] = 'wp_abilities_api_categories_init';
+
 		wp_register_ability_category(
 			'test-data-retrieval',
 			array(
@@ -130,6 +132,8 @@ public function register_test_ability_categories(): void {
 				)
 			);
 		}
+
+		array_pop( $wp_current_filter );
 	}
 
 	/**
diff --git a/tests/unit/rest-api/wpRestAbilitiesV1ListController.php b/tests/unit/rest-api/wpRestAbilitiesV1ListController.php
index a6e5d92..19e3522 100644
--- a/tests/unit/rest-api/wpRestAbilitiesV1ListController.php
+++ b/tests/unit/rest-api/wpRestAbilitiesV1ListController.php
@@ -37,8 +37,6 @@ public static function set_up_before_class(): void {
 			)
 		);
 
-		// Fire the init hook to allow test ability categories registration.
-		do_action( 'wp_abilities_api_categories_init' );
 		self::register_test_categories();
 	}
 
@@ -67,8 +65,6 @@ public function set_up(): void {
 
 		do_action( 'rest_api_init' );
 
-		// Initialize Abilities API.
-		do_action( 'wp_abilities_api_init' );
 		$this->register_test_abilities();
 
 		// Set default user for tests
@@ -99,6 +95,10 @@ public function tear_down(): void {
 	 * Register test categories for testing.
 	 */
 	public static function register_test_categories(): void {
+		// Simulates the init hook to allow test ability categories registration.
+		global $wp_current_filter;
+		$wp_current_filter[] = 'wp_abilities_api_categories_init';
+
 		wp_register_ability_category(
 			'math',
 			array(
@@ -122,6 +122,24 @@ public static function register_test_categories(): void {
 				'description' => 'General purpose abilities.',
 			)
 		);
+
+		array_pop( $wp_current_filter );
+	}
+
+	/**
+	 * Helper to register a test ability.
+	 *
+	 * @param string $name Ability name.
+	 * @param array  $args Ability arguments.
+	 */
+	private function register_test_ability( string $name, array $args ): void {
+		// Simulates the init hook to allow test abilities registration.
+		global $wp_current_filter;
+		$wp_current_filter[] = 'wp_abilities_api_init';
+
+		wp_register_ability( $name, $args );
+
+		array_pop( $wp_current_filter );
 	}
 
 	/**
@@ -129,7 +147,7 @@ public static function register_test_categories(): void {
 	 */
 	private function register_test_abilities(): void {
 		// Register a regular ability.
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/calculator',
 			array(
 				'label'               => 'Calculator',
@@ -173,7 +191,7 @@ private function register_test_abilities(): void {
 		);
 
 		// Register a read-only ability.
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/system-info',
 			array(
 				'label'               => 'System Info',
@@ -220,7 +238,7 @@ private function register_test_abilities(): void {
 		);
 
 		// Ability that does not show in REST.
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/not-show-in-rest',
 			array(
 				'label'               => 'Hidden from REST',
@@ -235,7 +253,7 @@ private function register_test_abilities(): void {
 
 		// Register multiple abilities for pagination testing
 		for ( $i = 1; $i <= 60; $i++ ) {
-			wp_register_ability(
+			$this->register_test_ability(
 				"test/ability-{$i}",
 				array(
 					'label'               => "Test Ability {$i}",
@@ -589,7 +607,7 @@ public function test_get_schema(): void {
 	 */
 	public function test_ability_name_with_valid_special_characters(): void {
 		// Register ability with hyphen (valid).
-		wp_register_ability(
+		$this->register_test_ability(
 			'test-hyphen/ability',
 			array(
 				'label'               => 'Test Hyphen Ability',
diff --git a/tests/unit/rest-api/wpRestAbilitiesV1RunController.php b/tests/unit/rest-api/wpRestAbilitiesV1RunController.php
index 40372fe..f4340f8 100644
--- a/tests/unit/rest-api/wpRestAbilitiesV1RunController.php
+++ b/tests/unit/rest-api/wpRestAbilitiesV1RunController.php
@@ -49,8 +49,6 @@ public static function set_up_before_class(): void {
 			)
 		);
 
-		// Fire the init hook to allow test ability categories registration.
-		do_action( 'wp_abilities_api_categories_init' );
 		self::register_test_categories();
 	}
 
@@ -78,8 +76,6 @@ public function set_up(): void {
 
 		do_action( 'rest_api_init' );
 
-		// Initialize Abilities API.
-		do_action( 'wp_abilities_api_init' );
 		$this->register_test_abilities();
 
 		// Set default user for tests
@@ -109,6 +105,10 @@ public function tear_down(): void {
 	 * Register test categories for testing.
 	 */
 	public static function register_test_categories(): void {
+		// Simulates the init hook to allow test ability category registration.
+		global $wp_current_filter;
+		$wp_current_filter[] = 'wp_abilities_api_categories_init';
+
 		wp_register_ability_category(
 			'math',
 			array(
@@ -132,6 +132,24 @@ public static function register_test_categories(): void {
 				'description' => 'General purpose abilities.',
 			)
 		);
+
+		array_pop( $wp_current_filter );
+	}
+
+	/**
+	 * Helper to register a test ability.
+	 *
+	 * @param string $name Ability name.
+	 * @param array  $args Ability arguments.
+	 */
+	private function register_test_ability( string $name, array $args ): void {
+		// Simulates the init hook to allow test abilities registration.
+		global $wp_current_filter;
+		$wp_current_filter[] = 'wp_abilities_api_init';
+
+		wp_register_ability( $name, $args );
+
+		array_pop( $wp_current_filter );
 	}
 
 	/**
@@ -139,7 +157,7 @@ public static function register_test_categories(): void {
 	 */
 	private function register_test_abilities(): void {
 		// Regular ability (POST only).
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/calculator',
 			array(
 				'label'               => 'Calculator',
@@ -176,7 +194,7 @@ private function register_test_abilities(): void {
 		);
 
 		// Read-only ability (GET method).
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/user-info',
 			array(
 				'label'               => 'User Info',
@@ -222,7 +240,7 @@ private function register_test_abilities(): void {
 		);
 
 		// Destructive ability (DELETE method).
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/delete-user',
 			array(
 				'label'               => 'Delete User',
@@ -263,7 +281,7 @@ private function register_test_abilities(): void {
 		);
 
 		// Ability with contextual permissions
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/restricted',
 			array(
 				'label'               => 'Restricted Action',
@@ -294,7 +312,7 @@ private function register_test_abilities(): void {
 		);
 
 		// Ability that does not show in REST.
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/not-show-in-rest',
 			array(
 				'label'               => 'Hidden from REST',
@@ -308,7 +326,7 @@ private function register_test_abilities(): void {
 		);
 
 		// Ability that returns null
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/null-return',
 			array(
 				'label'               => 'Null Return',
@@ -325,7 +343,7 @@ private function register_test_abilities(): void {
 		);
 
 		// Ability that returns WP_Error
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/error-return',
 			array(
 				'label'               => 'Error Return',
@@ -342,7 +360,7 @@ private function register_test_abilities(): void {
 		);
 
 		// Ability with invalid output
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/invalid-output',
 			array(
 				'label'               => 'Invalid Output',
@@ -362,7 +380,7 @@ private function register_test_abilities(): void {
 		);
 
 		// Read-only ability for query params testing.
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/query-params',
 			array(
 				'label'               => 'Query Params Test',
@@ -463,7 +481,7 @@ public function test_execute_destructive_ability_delete(): void {
 	 * @ticket 64098
 	 */
 	public function test_regular_ability_requires_post(): void {
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/open-tool',
 			array(
 				'label'               => 'Open Tool',
@@ -793,7 +811,7 @@ public function test_post_request_with_non_array_input(): void {
 	 */
 	public function test_output_validation_failure_returns_error(): void {
 		// Register ability with strict output schema.
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/strict-output',
 			array(
 				'label'               => 'Strict Output',
@@ -842,7 +860,7 @@ public function test_output_validation_failure_returns_error(): void {
 	 */
 	public function test_input_validation_failure_returns_error(): void {
 		// Register ability with strict input schema.
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/strict-input',
 			array(
 				'label'               => 'Strict Input',
@@ -891,7 +909,7 @@ public function test_input_validation_failure_returns_error(): void {
 	 */
 	public function test_ability_without_annotations_defaults_to_post_method(): void {
 		// Register ability without annotations.
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/no-annotations',
 			array(
 				'label'               => 'No Annotations',
@@ -926,7 +944,7 @@ public function test_ability_without_annotations_defaults_to_post_method(): void
 	 * @ticket 64098
 	 */
 	public function test_empty_input_handling_get_method(): void {
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/read-only-empty',
 			array(
 				'label'               => 'Read-only Empty',
@@ -958,7 +976,7 @@ public function test_empty_input_handling_get_method(): void {
 	 * @ticket 64098
 	 */
 	public function test_empty_input_handling_get_method_with_normalized_input(): void {
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/read-only-empty-array',
 			array(
 				'label'               => 'Read-only Empty Array',
@@ -994,7 +1012,7 @@ public function test_empty_input_handling_get_method_with_normalized_input(): vo
 	 * @ticket 64098
 	 */
 	public function test_empty_input_handling_post_method(): void {
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/regular-empty',
 			array(
 				'label'               => 'Regular Empty',
@@ -1065,7 +1083,7 @@ public function test_malformed_json_post_body( string $json ): void {
 	 */
 	public function test_php_type_strings_in_input(): void {
 		// Register ability that accepts any input
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/echo',
 			array(
 				'label'               => 'Echo',
@@ -1114,7 +1132,7 @@ public function test_php_type_strings_in_input(): void {
 	 */
 	public function test_mixed_encoding_in_input(): void {
 		// Register ability that accepts any input
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/echo-encoding',
 			array(
 				'label'               => 'Echo Encoding',
@@ -1183,7 +1201,7 @@ public function data_invalid_http_methods_provider(): array {
 	 */
 	public function test_invalid_http_methods( string $method ): void {
 		// Register an ability with no permission requirements for this test
-		wp_register_ability(
+		$this->register_test_ability(
 			'test/method-test',
 			array(
 				'label'               => 'Method Test',