Update OpenTelemetry GenAI conventions to latest

.github/aw/actions-lock.json

@@ -0,0 +1,14 @@
+{
+  "entries": {
+    "actions/github-script@v9.0.0": {
+      "repo": "actions/github-script",
+      "version": "v9.0.0",
+      "sha": "3a2844b7e9c422d3c10d287c895573f7108da1b3"
+    },
+    "github/gh-aw-actions/setup@v0.80.9": {
+      "repo": "github/gh-aw-actions/setup",
+      "version": "v0.80.9",
+      "sha": "8c7d04ebf1ece56cd381446125da3e0f6896294a"
+    }
+  }
+}

.github/skills/update-otel-genai-conventions/SKILL.md

@@ -353,7 +353,7 @@ Critical knowledge from past PR reviews that should inform all modes:
 - **No CHANGELOGs**: This repository no longer maintains per-library CHANGELOG.md files. Do NOT create or update any CHANGELOG files.
 - **Source-generated JSON**: Adding new OTel part types requires: (1) new inner class, (2) `[JsonSerializable]` registration on `OtelContext`, (3) switch case in `SerializeChatMessages()`.
 - **LoggerMessage text**: When using `[LoggerMessage]`, the message text should match the OTel event name for console logger readability.
-- **No orphan constants**: Never add a constant to `OpenTelemetryConsts.cs` unless the same PR also adds at least one emission site for it. If the convention defines an attribute that no current client populates, classify the change as 🟢 *Constant not yet emitted* and defer the constant — do not add it ahead of emission. Verify with `grep -rn NewConstantName src/Libraries/Microsoft.Extensions.AI/` before submitting.
+- **No orphan constants**: Never add a constant to `OpenTelemetryConsts.cs` unless the same PR also adds at least one emission site for it. If the convention defines an attribute that no current client populates, classify the change as 🟢 *Constant not yet emitted* and defer the constant — do not add it ahead of emission. Verify with `grep -rn NewConstantName src/Libraries/Microsoft.Extensions.AI/` before submitting. This defer rule applies **only** to brand-new attributes/metrics that have no emission site. A change to a convention item the code **already emits** — a type/unit change (e.g. `gen_ai.request.top_k` `double` → `int`), a requiredness/scope change, a rename, a sampling-relevance change, or a new well-known value for an already-emitted attribute — is actionable and must be applied in the same pass, not deferred. Deferral marks individual constants; it is never a reason to skip the overall update.
 - **Area-aware constants**: Pick the nested class in `OpenTelemetryConsts.cs` based on the upstream area: `GenAI.*` for `gen-ai/*`, `MCP.*` for `mcp/*`. Provider-specific attributes (`openai.*`, `anthropic.*`, `aws-bedrock.*`, `azure-ai-inference.*`) generally belong in the **provider package's** constants file, not in `Microsoft.Extensions.AI/OpenTelemetryConsts.cs`. See [references/implementation-patterns.md §Area placement guidance](references/implementation-patterns.md#area-placement-guidance).
 
 ## Validation

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

@@ -353,6 +353,11 @@ public override async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseA
                         _ = activity.AddTag(OpenTelemetryConsts.GenAI.Request.TopP, top_p);
                     }
 
+                    if (options.Reasoning?.Effort is ReasoningEffort reasoningEffort)
+                    {
+                        _ = activity.AddTag(OpenTelemetryConsts.GenAI.Request.ReasoningLevel, reasoningEffort.ToString().ToLowerInvariant());
+                    }
+
                     if (options.ResponseFormat is not null)
                     {
                         switch (options.ResponseFormat)

src/Libraries/Microsoft.Extensions.AI/Common/OtelMessageSerializer.cs

@@ -268,6 +268,7 @@ internal static string SerializeChatMessages(
                     topLevel.Equals("image", StringComparison.OrdinalIgnoreCase) ? "image" :
                     topLevel.Equals("audio", StringComparison.OrdinalIgnoreCase) ? "audio" :
                     topLevel.Equals("video", StringComparison.OrdinalIgnoreCase) ? "video" :
+                    topLevel.Equals("application", StringComparison.OrdinalIgnoreCase) ? "document" :
                     null;
             }
         }

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

@@ -132,6 +132,7 @@ public static class Request
             public const string Temperature = "gen_ai.request.temperature";
             public const string TopK = "gen_ai.request.top_k";
             public const string TopP = "gen_ai.request.top_p";
+            public const string ReasoningLevel = "gen_ai.request.reasoning.level";
         }
 
         public static class Response

test/Libraries/Microsoft.Extensions.AI.Tests/ChatCompletion/OpenTelemetryChatClientTests.cs

@@ -131,6 +131,7 @@ async static IAsyncEnumerable<ChatResponseUpdate> CallbackAsync(
             Temperature = 6.0f,
             Seed = 42,
             StopSequences = ["hello", "world"],
+            Reasoning = new ReasoningOptions { Effort = ReasoningEffort.High },
             AdditionalProperties = new()
             {
                 ["service_tier"] = "value1",
@@ -183,6 +184,7 @@ async static IAsyncEnumerable<ChatResponseUpdate> CallbackAsync(
         Assert.Equal(enableSensitiveData ? "value1" : null, activity.GetTagItem("service_tier"));
         Assert.Equal(enableSensitiveData ? "value2" : null, activity.GetTagItem("SomethingElse"));
         Assert.Equal(42L, activity.GetTagItem("gen_ai.request.seed"));
+        Assert.Equal("high", activity.GetTagItem("gen_ai.request.reasoning.level"));
 
         Assert.Equal("id123", activity.GetTagItem("gen_ai.response.id"));
         Assert.Equal("""["stop"]""", activity.GetTagItem("gen_ai.response.finish_reasons"));
@@ -445,6 +447,7 @@ async static IAsyncEnumerable<ChatResponseUpdate> CallbackAsync(
                 new TextReasoningContent("User reasoning"),
                 new DataContent(Convert.FromBase64String("ZGF0YSBjb250ZW50"), "audio/mp3"),
                 new UriContent(new Uri("https://example.com/video.mp4"), "video/mp4"),
+                new DataContent(Convert.FromBase64String("cGRmIGRhdGE="), "application/pdf"),
                 new HostedFileContent("file-xyz789"),
             ]),
             new(ChatRole.Assistant, [new FunctionCallContent("call-456", "SearchFiles")]),
@@ -492,6 +495,12 @@ async static IAsyncEnumerable<ChatResponseUpdate> CallbackAsync(
                     "mime_type": "video/mp4",
                     "modality": "video"
                   },
+                  {
+                    "type": "blob",
+                    "content": "cGRmIGRhdGE=",
+                    "mime_type": "application/pdf",
+                    "modality": "document"
+                  },
                   {
                     "type": "file",
                     "file_id": "file-xyz789"