feat(core): introduce Kind.Agent for sub-agent classification (#20369)

packages/core/src/agents/subagent-tool-wrapper.test.ts

@@ -70,7 +70,7 @@ describe('SubagentToolWrapper', () => {
       expect(wrapper.name).toBe(mockDefinition.name);
       expect(wrapper.displayName).toBe(mockDefinition.displayName);
       expect(wrapper.description).toBe(mockDefinition.description);
-      expect(wrapper.kind).toBe(Kind.Think);
+      expect(wrapper.kind).toBe(Kind.Agent);
       expect(wrapper.isOutputMarkdown).toBe(true);
       expect(wrapper.canUpdateOutput).toBe(true);
     });

packages/core/src/agents/subagent-tool-wrapper.ts

@@ -45,7 +45,7 @@ export class SubagentToolWrapper extends BaseDeclarativeTool<
       definition.name,
       definition.displayName ?? definition.name,
       definition.description,
-      Kind.Think,
+      Kind.Agent,
       definition.inputConfig.inputSchema,
       messageBus,
       /* isOutputMarkdown */ true,

packages/core/src/agents/subagent-tool.test.ts

@@ -7,6 +7,7 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { SubagentTool } from './subagent-tool.js';
 import { SubagentToolWrapper } from './subagent-tool-wrapper.js';
+import { Kind } from '../tools/tools.js';
 import type {
   LocalAgentDefinition,
   RemoteAgentDefinition,
@@ -70,6 +71,11 @@ describe('SubAgentInvocation', () => {
       .mockReturnValue(mockInnerInvocation);
   });
 
+  it('should have Kind.Agent', () => {
+    const tool = new SubagentTool(testDefinition, mockConfig, mockMessageBus);
+    expect(tool.kind).toBe(Kind.Agent);
+  });
+
   it('should delegate shouldConfirmExecute to the inner sub-invocation (local)', async () => {
     const tool = new SubagentTool(testDefinition, mockConfig, mockMessageBus);
     const params = {};

packages/core/src/agents/subagent-tool.ts

@@ -41,7 +41,7 @@ export class SubagentTool extends BaseDeclarativeTool<AgentInputs, ToolResult> {
       definition.name,
       definition.displayName ?? definition.name,
       definition.description,
-      Kind.Think,
+      Kind.Agent,
       inputSchema,
       messageBus,
       /* isOutputMarkdown */ true,