feat(mcp): Return structured output from get_event_stacktrace

docs/contributing/tool-responses.md

@@ -163,6 +163,16 @@ frame (the last in-app frame of the raised exception or the thread) gets
 to 200 characters of JSON. Request headers, cookies and body, frame addresses, symbols
 and source links, tag search queries, and external issue link ids stay out.
 
+### Event Stacktrace
+
+`get_event_stacktrace` returns one thread under `thread`, using the same frame
+and thread shapes as `get_issue_details`, with `selection.status` saying how the
+`thread` selector resolved. When the selector matches no thread or several,
+`thread` is null, `selection.message` says why, and `availableThreads` lists
+every thread summary. Only the thread's most relevant frame (its last in-app
+frame) gets pre/post context and variables. Held locks,
+registers and the raw (unsymbolicated) stacktrace stay out.
+
 ### Profile Details
 
 `get_profile_details` returns one profile summary under `profile`,

packages/mcp-core/src/internal/formatting.ts

@@ -698,111 +698,13 @@ function formatThreadTable(
   ];
 }
 
-export function formatAvailableThreadList(
-  threads: z.infer<typeof ThreadEntrySchema>[],
-): string {
-  return [
-    "## Available Threads",
-    "",
-    ...formatThreadTable(threads),
-    "",
-    "Pass `thread` as a numeric Thread ID or exact thread Name.",
-  ].join("\n");
-}
-
 export function parseThreadsEntryData(
   data: unknown,
 ): z.infer<typeof ThreadsEntrySchema> | undefined {
   const result = ThreadsEntrySchema.safeParse(data);
   return result.success ? result.data : undefined;
 }
 
-/**
- * Formats the selected thread stacktrace using the same frame rendering
- * conventions as issue event details.
- */
-export function formatThreadStacktraceOutput({
-  event,
-  thread,
-  selectionReason,
-}: {
-  event: Event;
-  thread: z.infer<typeof ThreadEntrySchema>;
-  selectionReason: string;
-}): string {
-  const parts: string[] = [];
-
-  parts.push("## Selected Thread");
-  parts.push("");
-  parts.push(`**Selection**: ${selectionReason}`);
-  parts.push(`**Thread ID**: ${getThreadDisplayValue(thread.id)}`);
-  parts.push(`**Name**: ${getThreadDisplayValue(thread.name)}`);
-  parts.push(`**State**: ${getThreadDisplayValue(thread.state)}`);
-  parts.push(`**Crashed**: ${getThreadDisplayValue(thread.crashed)}`);
-  parts.push(`**Current**: ${getThreadDisplayValue(thread.current)}`);
-  parts.push("");
-
-  const frames = thread.stacktrace?.frames;
-  if (!frames || frames.length === 0) {
-    parts.push("No stacktrace is available for the selected thread.");
-    parts.push("");
-    return parts.join("\n");
-  }
-
-  parts.push("## Stacktrace");
-  parts.push("");
-  const framesOmitted = formatFramesOmitted(thread.stacktrace?.framesOmitted);
-  if (framesOmitted) {
-    parts.push(`**Frames Omitted**: ${framesOmitted}`);
-    parts.push("");
-  }
-
-  const relevantFrame = findMostRelevantInAppFrame(frames);
-  if (relevantFrame && (relevantFrame.context?.length || relevantFrame.vars)) {
-    parts.push(renderEnhancedFrame(relevantFrame, event));
-    parts.push("");
-    parts.push("**Full Stacktrace:**");
-    parts.push("────────────────");
-  } else {
-    parts.push("**Full Stacktrace:**");
-  }
-
-  parts.push(
-    codeBlock(
-      frames
-        .map((frame) => {
-          const header = formatFrameHeader(frame, undefined, event.platform);
-          const context = renderInlineContext(frame);
-          return `${header}${context}`;
-        })
-        .join("\n"),
-    ),
-  );
-  parts.push("");
-
-  return parts.join("\n");
-}
-
-function formatFramesOmitted(
-  framesOmitted: unknown[] | null | undefined,
-): string | null {
-  if (!framesOmitted?.length) {
-    return null;
-  }
-
-  const [firstOmitted, lastOmitted] = framesOmitted;
-  if (
-    typeof firstOmitted === "number" &&
-    typeof lastOmitted === "number" &&
-    Number.isFinite(firstOmitted) &&
-    Number.isFinite(lastOmitted)
-  ) {
-    return String(Math.max(0, lastOmitted - firstOmitted));
-  }
-
-  return null;
-}
-
 /**
  * Renders surrounding source code context for a stack frame.
  * Shows a window of code lines around the error line with visual indicators.

packages/mcp-core/src/server.metadata.test.ts

@@ -40,8 +40,6 @@ const ALLOWED_TOOL_META: Record<string, readonly string[]> = {
 const OUTPUT_SCHEMA_EXEMPT: Record<string, string> = {
   get_trace_details:
     "markdown-only by policy (docs/contributing/tool-responses.md)",
-  get_event_stacktrace:
-    "markdown-only by policy (docs/contributing/tool-responses.md)",
   get_span_details: "delegates to the get_trace_details renderer",
   get_doc: "returns doc text",
   get_snapshot_image: "returns an image",

packages/mcp-core/src/server.test.ts

@@ -2152,9 +2152,10 @@ describe("buildServer", () => {
         },
       });
 
-      expect(getTextContent(result)).toContain(
-        "# Event Stacktrace in **sentry-mcp-evals**",
-      );
+      expect(result.structuredContent).toMatchObject({
+        organizationSlug: "sentry-mcp-evals",
+        issueId: "CLOUDFLARE-MCP-41",
+      });
     });
 
     it("execute_sentry_tool dispatches to catalog-only issue user reports", async () => {

packages/mcp-core/src/skillDefinitions.json

@@ -89,7 +89,7 @@
       },
       {
         "name": "get_event_stacktrace",
-        "description": "Get the full stack trace (stacktrace) for one thread of a specific Sentry event.\n\nUse this tool when you need to:\n- Fetch the full stacktrace for a thread listed in issue details\n- Inspect a non-crashed thread from an event with multiple threads\n- Get Sentry's default selected thread stacktrace when no thread is specified\n\n<examples>\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123')\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', eventId='c49541c747cb4d8aa3efb70ca5aba243', thread=259)\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', thread='main')\n</examples>\n\n<hints>\n- `thread` is optional. If omitted, this returns the same default thread Sentry selects: first crashed thread, then first thread with a stacktrace, then first thread.\n- Pass `thread` as a numeric Thread ID or exact thread Name from the issue details thread list.\n- If the issue details show only one useful thread, omit `thread`.\n</hints>",
+        "description": "Get the full stack trace (stacktrace) for one thread of a specific Sentry event.\n\nUse this tool when you need to:\n- Fetch the full stacktrace for a thread listed in issue details\n- Inspect a non-crashed thread from an event with multiple threads\n- Get Sentry's default selected thread stacktrace when no thread is specified\n\n<examples>\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123')\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', eventId='c49541c747cb4d8aa3efb70ca5aba243', thread=259)\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', thread='main')\n</examples>\n\n<hints>\n- `thread` is optional. If omitted, this returns the same default thread Sentry selects: first crashed thread, then first thread with a stacktrace, then first thread.\n- Pass `thread` as a numeric Thread ID or exact thread Name from the issue details thread list.\n- If the issue details show only one useful thread, omit `thread`.\n- When the selector matches no thread or several, `thread` is null and `availableThreads` lists every thread.\n</hints>",
         "requiredScopes": ["event:read"]
       },
       {
@@ -279,7 +279,7 @@
       },
       {
         "name": "get_event_stacktrace",
-        "description": "Get the full stack trace (stacktrace) for one thread of a specific Sentry event.\n\nUse this tool when you need to:\n- Fetch the full stacktrace for a thread listed in issue details\n- Inspect a non-crashed thread from an event with multiple threads\n- Get Sentry's default selected thread stacktrace when no thread is specified\n\n<examples>\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123')\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', eventId='c49541c747cb4d8aa3efb70ca5aba243', thread=259)\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', thread='main')\n</examples>\n\n<hints>\n- `thread` is optional. If omitted, this returns the same default thread Sentry selects: first crashed thread, then first thread with a stacktrace, then first thread.\n- Pass `thread` as a numeric Thread ID or exact thread Name from the issue details thread list.\n- If the issue details show only one useful thread, omit `thread`.\n</hints>",
+        "description": "Get the full stack trace (stacktrace) for one thread of a specific Sentry event.\n\nUse this tool when you need to:\n- Fetch the full stacktrace for a thread listed in issue details\n- Inspect a non-crashed thread from an event with multiple threads\n- Get Sentry's default selected thread stacktrace when no thread is specified\n\n<examples>\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123')\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', eventId='c49541c747cb4d8aa3efb70ca5aba243', thread=259)\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', thread='main')\n</examples>\n\n<hints>\n- `thread` is optional. If omitted, this returns the same default thread Sentry selects: first crashed thread, then first thread with a stacktrace, then first thread.\n- Pass `thread` as a numeric Thread ID or exact thread Name from the issue details thread list.\n- If the issue details show only one useful thread, omit `thread`.\n- When the selector matches no thread or several, `thread` is null and `availableThreads` lists every thread.\n</hints>",
         "requiredScopes": ["event:read"]
       },
       {
@@ -430,7 +430,7 @@
       },
       {
         "name": "get_event_stacktrace",
-        "description": "Get the full stack trace (stacktrace) for one thread of a specific Sentry event.\n\nUse this tool when you need to:\n- Fetch the full stacktrace for a thread listed in issue details\n- Inspect a non-crashed thread from an event with multiple threads\n- Get Sentry's default selected thread stacktrace when no thread is specified\n\n<examples>\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123')\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', eventId='c49541c747cb4d8aa3efb70ca5aba243', thread=259)\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', thread='main')\n</examples>\n\n<hints>\n- `thread` is optional. If omitted, this returns the same default thread Sentry selects: first crashed thread, then first thread with a stacktrace, then first thread.\n- Pass `thread` as a numeric Thread ID or exact thread Name from the issue details thread list.\n- If the issue details show only one useful thread, omit `thread`.\n</hints>",
+        "description": "Get the full stack trace (stacktrace) for one thread of a specific Sentry event.\n\nUse this tool when you need to:\n- Fetch the full stacktrace for a thread listed in issue details\n- Inspect a non-crashed thread from an event with multiple threads\n- Get Sentry's default selected thread stacktrace when no thread is specified\n\n<examples>\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123')\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', eventId='c49541c747cb4d8aa3efb70ca5aba243', thread=259)\nget_event_stacktrace(organizationSlug='my-org', issueId='PROJECT-123', thread='main')\n</examples>\n\n<hints>\n- `thread` is optional. If omitted, this returns the same default thread Sentry selects: first crashed thread, then first thread with a stacktrace, then first thread.\n- Pass `thread` as a numeric Thread ID or exact thread Name from the issue details thread list.\n- If the issue details show only one useful thread, omit `thread`.\n- When the selector matches no thread or several, `thread` is null and `availableThreads` lists every thread.\n</hints>",
         "requiredScopes": ["event:read"]
       },
       {