feat(plan): update planning workflow to encourage multi-select with descriptions of options

packages/core/src/core/__snapshots__/prompts.test.ts.snap

@@ -123,7 +123,7 @@ Plan Mode uses an adaptive planning workflow where the research depth, plan stru
 Analyze requirements and use search/read tools to explore the codebase. Systematically map affected modules, trace data flow, and identify dependencies.
 
 ### 2. Consult
-The depth of your consultation should be proportional to the task's complexity:
+The depth of your consultation should be proportional to the task's complexity. Use multi-select to offer flexibility and include detailed descriptions for each option to help the user understand the implications of their choice.
 - **Simple Tasks:** Skip consultation and proceed directly to drafting.
 - **Standard Tasks:** If multiple viable approaches exist, present a concise summary (including pros/cons and your recommendation) via \`ask_user\` and wait for a decision.
 - **Complex Tasks:** You MUST present at least two viable approaches with detailed trade-offs via \`ask_user\` and obtain approval before drafting the plan.
@@ -291,7 +291,7 @@ Plan Mode uses an adaptive planning workflow where the research depth, plan stru
 Analyze requirements and use search/read tools to explore the codebase. Systematically map affected modules, trace data flow, and identify dependencies.
 
 ### 2. Consult
-The depth of your consultation should be proportional to the task's complexity:
+The depth of your consultation should be proportional to the task's complexity. Use multi-select to offer flexibility and include detailed descriptions for each option to help the user understand the implications of their choice.
 - **Simple Tasks:** Skip consultation and proceed directly to drafting.
 - **Standard Tasks:** If multiple viable approaches exist, present a concise summary (including pros/cons and your recommendation) via \`ask_user\` and wait for a decision.
 - **Complex Tasks:** You MUST present at least two viable approaches with detailed trade-offs via \`ask_user\` and obtain approval before drafting the plan.
@@ -578,7 +578,7 @@ Plan Mode uses an adaptive planning workflow where the research depth, plan stru
 Analyze requirements and use search/read tools to explore the codebase. Systematically map affected modules, trace data flow, and identify dependencies.
 
 ### 2. Consult
-The depth of your consultation should be proportional to the task's complexity:
+The depth of your consultation should be proportional to the task's complexity. Use multi-select to offer flexibility and include detailed descriptions for each option to help the user understand the implications of their choice.
 - **Simple Tasks:** Skip consultation and proceed directly to drafting.
 - **Standard Tasks:** If multiple viable approaches exist, present a concise summary (including pros/cons and your recommendation) via \`ask_user\` and wait for a decision.
 - **Complex Tasks:** You MUST present at least two viable approaches with detailed trade-offs via \`ask_user\` and obtain approval before drafting the plan.

packages/core/src/prompts/snippets.ts

@@ -486,7 +486,7 @@ Plan Mode uses an adaptive planning workflow where the research depth, plan stru
 Analyze requirements and use search/read tools to explore the codebase. Systematically map affected modules, trace data flow, and identify dependencies.
 
 ### 2. Consult
-The depth of your consultation should be proportional to the task's complexity:
+The depth of your consultation should be proportional to the task's complexity. Use multi-select to offer flexibility and include detailed descriptions for each option to help the user understand the implications of their choice.
 - **Simple Tasks:** Skip consultation and proceed directly to drafting.
 - **Standard Tasks:** If multiple viable approaches exist, present a concise summary (including pros/cons and your recommendation) via ${formatToolName(ASK_USER_TOOL_NAME)} and wait for a decision.
 - **Complex Tasks:** You MUST present at least two viable approaches with detailed trade-offs via ${formatToolName(ASK_USER_TOOL_NAME)} and obtain approval before drafting the plan.

packages/core/src/tools/definitions/__snapshots__/coreToolsModelSnapshots.test.ts.snap

@@ -859,7 +859,7 @@ exports[`coreTools snapshots for specific models > Model: gemini-3-pro-preview >
 
 exports[`coreTools snapshots for specific models > Model: gemini-3-pro-preview > snapshot for tool: ask_user 1`] = `
 {
-  "description": "Ask the user one or more questions to gather preferences, clarify requirements, or make decisions.",
+  "description": "Ask the user one or more questions to gather preferences, clarify requirements, or make decisions. When using this tool, prefer providing multiple-choice options with detailed descriptions and enable multi-select where appropriate to provide maximum flexibility.",
   "name": "ask_user",
   "parametersJsonSchema": {
     "properties": {

packages/core/src/tools/definitions/model-family-sets/gemini-3.ts

@@ -558,7 +558,7 @@ The agent did not use the todo list because this task could be completed by a ti
   ask_user: {
     name: ASK_USER_TOOL_NAME,
     description:
-      'Ask the user one or more questions to gather preferences, clarify requirements, or make decisions.',
+      'Ask the user one or more questions to gather preferences, clarify requirements, or make decisions. When using this tool, prefer providing multiple-choice options with detailed descriptions and enable multi-select where appropriate to provide maximum flexibility.',
     parametersJsonSchema: {
       type: 'object',
       required: ['questions'],