feat(core): persist subagent agentId in tool call records (#25092)

packages/core/src/agents/local-executor.ts

@@ -114,7 +114,7 @@ export function createUnauthorizedToolError(toolName: string): string {
 export class LocalAgentExecutor<TOutput extends z.ZodTypeAny> {
   readonly definition: LocalAgentDefinition<TOutput>;
 
-  private readonly agentId: string;
+  readonly agentId: string;
   private readonly toolRegistry: ToolRegistry;
   private readonly promptRegistry: PromptRegistry;
   private readonly resourceRegistry: ResourceRegistry;

packages/core/src/agents/local-invocation.test.ts

@@ -79,6 +79,7 @@ describe('LocalSubagentInvocation', () => {
     mockExecutorInstance = {
       run: vi.fn(),
       definition: testDefinition,
+      agentId: 'test-agent-id',
     } as unknown as Mocked<LocalAgentExecutor<z.ZodUnknown>>;
 
     MockLocalAgentExecutor.create.mockResolvedValue(

packages/core/src/agents/local-invocation.ts

@@ -25,12 +25,14 @@ import {
   isToolActivityError,
 } from './types.js';
 import { randomUUID } from 'node:crypto';
+import type { z } from 'zod';
 import type { MessageBus } from '../confirmation-bus/message-bus.js';
 import {
   sanitizeThoughtContent,
   sanitizeToolArgs,
   sanitizeErrorMessage,
 } from '../utils/agent-sanitization-utils.js';
+import { debugLogger } from '../utils/debugLogger.js';
 
 const INPUT_PREVIEW_MAX_LENGTH = 50;
 const DESCRIPTION_MAX_LENGTH = 200;
@@ -108,6 +110,7 @@ export class LocalSubagentInvocation extends BaseToolInvocation<
     updateOutput?: (output: ToolLiveOutput) => void,
   ): Promise<ToolResult> {
     const recentActivity: SubagentActivityItem[] = [];
+    let executor: LocalAgentExecutor<z.ZodUnknown> | undefined;
 
     try {
       if (updateOutput) {
@@ -273,7 +276,7 @@ export class LocalSubagentInvocation extends BaseToolInvocation<
         }
       };
 
-      const executor = await LocalAgentExecutor.create(
+      executor = await LocalAgentExecutor.create(
         this.definition,
         this.context,
         onActivity,
@@ -319,11 +322,14 @@ ${output.result}`;
       return {
         llmContent: [{ text: resultContent }],
         returnDisplay: progress,
+        data: { agentId: executor.agentId },
       };
     } catch (error) {
       const errorMessage =
         error instanceof Error ? error.message : String(error);
 
+      debugLogger.error(`Subagent '${this.definition.name}' failed:`, error);
+
       const isAbort =
         (error instanceof Error && error.name === 'AbortError') ||
         errorMessage.includes('Aborted');
@@ -369,6 +375,7 @@ ${output.result}`;
       return {
         llmContent: `Subagent '${this.definition.name}' failed. Error: ${errorMessage}`,
         returnDisplay: progress,
+        data: executor ? { agentId: executor.agentId } : undefined,
         // We omit the 'error' property so that the UI renders our rich returnDisplay
         // instead of the raw error message. The llmContent still informs the agent of the failure.
       };