Update OpenTelemetryChatClient/EmbeddingGenerator to v1.31 of genai standard convention (#6073)

Author: stephentoub

src/Libraries/Microsoft.Extensions.AI/ChatCompletion/OpenTelemetryChatClient.cs

@@ -23,7 +23,7 @@ namespace Microsoft.Extensions.AI;
 
 /// <summary>Represents a delegating chat client that implements the OpenTelemetry Semantic Conventions for Generative AI systems.</summary>
 /// <remarks>
-/// This class provides an implementation of the Semantic Conventions for Generative AI systems v1.30, defined at <see href="https://opentelemetry.io/docs/specs/semconv/gen-ai/" />.
+/// This class provides an implementation of the Semantic Conventions for Generative AI systems v1.31, defined at <see href="https://opentelemetry.io/docs/specs/semconv/gen-ai/" />.
 /// The specification is still experimental and subject to change; as such, the telemetry output by this client is also subject to change.
 /// </remarks>
 public sealed partial class OpenTelemetryChatClient : DelegatingChatClient
@@ -279,20 +279,21 @@ public override async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseA
                         _ = activity.AddTag(OpenTelemetryConsts.GenAI.Request.TopP, top_p);
                     }
 
-                    if (_system is not null)
+                    if (options.ResponseFormat is not null)
                     {
-                        if (options.ResponseFormat is not null)
+                        switch (options.ResponseFormat)
                         {
-                            string responseFormat = options.ResponseFormat switch
-                            {
-                                ChatResponseFormatText => "text",
-                                ChatResponseFormatJson { Schema: null } => "json_schema",
-                                ChatResponseFormatJson => "json_object",
-                                _ => "_OTHER",
-                            };
-                            _ = activity.AddTag(OpenTelemetryConsts.GenAI.Request.PerProvider(_system, "response_format"), responseFormat);
+                            case ChatResponseFormatText:
+                                _ = activity.AddTag(OpenTelemetryConsts.GenAI.Output.Type, "text");
+                                break;
+                            case ChatResponseFormatJson:
+                                _ = activity.AddTag(OpenTelemetryConsts.GenAI.Output.Type, "json");
+                                break;
                         }
+                    }
 
+                    if (_system is not null)
+                    {
                         if (options.AdditionalProperties is { } props)
                         {
                             // Log all additional request options as per-provider tags. This is non-normative, but it covers cases where

src/Libraries/Microsoft.Extensions.AI/Embeddings/OpenTelemetryEmbeddingGenerator.cs

@@ -16,7 +16,7 @@ namespace Microsoft.Extensions.AI;
 
 /// <summary>Represents a delegating embedding generator that implements the OpenTelemetry Semantic Conventions for Generative AI systems.</summary>
 /// <remarks>
-/// This class provides an implementation of the Semantic Conventions for Generative AI systems v1.30, defined at <see href="https://opentelemetry.io/docs/specs/semconv/gen-ai/" />.
+/// This class provides an implementation of the Semantic Conventions for Generative AI systems v1.31, defined at <see href="https://opentelemetry.io/docs/specs/semconv/gen-ai/" />.
 /// The specification is still experimental and subject to change; as such, the telemetry output by this client is also subject to change.
 /// </remarks>
 /// <typeparam name="TInput">The type of input used to produce embeddings.</typeparam>

src/Libraries/Microsoft.Extensions.AI/OpenTelemetryConsts.cs

@@ -59,6 +59,11 @@ public static class Operation
             public const string Name = "gen_ai.operation.name";
         }
 
+        public static class Output
+        {
+            public const string Type = "gen_ai.output.type";
+        }
+
         public static class Request
         {
             public const string EmbeddingDimensions = "gen_ai.request.embedding.dimensions";