refactor(core): rename task tool to agent

- Update tool name aliases to map 'task' to 'agent' as legacy alias
- Add proper 'agent' tool name aliases (Agent, AgentTool)
- Update canonical-to-rule display mapping from 'task' to 'Agent'
- Update tests to expect 'agent' instead of 'task'
- Fix debug log message from [TaskTool] to [Agent]

This completes the tool renaming from "task" to "agent" for clarity,
as "agent" better describes the tool's purpose of delegating to
subagents.

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

integration-tests/sdk-typescript/subagents.test.ts

@@ -305,7 +305,7 @@ OTHER AGENTS CANNOT:
 
           if (isSDKAssistantMessage(message)) {
             // Check for task tool use in content blocks (main agent calling subagent)
-            const taskToolBlocks = findToolUseBlocks(message, 'task');
+            const taskToolBlocks = findToolUseBlocks(message, 'agent');
             if (taskToolBlocks.length > 0) {
               foundTaskTool = true;
               taskToolUseId = taskToolBlocks[0].id;
@@ -399,7 +399,7 @@ OTHER AGENTS CANNOT:
             // Check for task tool use (main agent delegating to subagent)
             const toolUseBlock = message.message.content.find(
               (block: ContentBlock): block is ToolUseBlock =>
-                block.type === 'tool_use' && block.name === 'task',
+                block.type === 'tool_use' && block.name === 'agent',
             );
             if (toolUseBlock) {
               foundTaskTool = true;

packages/core/src/permissions/permission-manager.test.ts

@@ -49,7 +49,15 @@ describe('resolveToolName', () => {
   });
 
   it('resolves Agent category', () => {
-    expect(resolveToolName('Agent')).toBe('task');
+    expect(resolveToolName('Agent')).toBe('agent');
+    expect(resolveToolName('agent')).toBe('agent');
+    expect(resolveToolName('AgentTool')).toBe('agent');
+  });
+
+  it('resolves legacy task aliases to agent', () => {
+    expect(resolveToolName('task')).toBe('agent');
+    expect(resolveToolName('Task')).toBe('agent');
+    expect(resolveToolName('TaskTool')).toBe('agent');
   });
 
   it('returns unknown names unchanged', () => {
@@ -158,7 +166,7 @@ describe('parseRule', () => {
 
   it('parses Agent with literal specifier', () => {
     const r = parseRule('Agent(Explore)');
-    expect(r.toolName).toBe('task');
+    expect(r.toolName).toBe('agent');
     expect(r.specifier).toBe('Explore');
     expect(r.specifierKind).toBe('literal');
   });
@@ -798,7 +806,7 @@ describe('PermissionManager', () => {
     it('returns default for unmatched tool', () => {
       // Note: 'glob' is covered by ReadFileTool via Read meta-category,
       // so use a tool not in any rule or meta-category
-      expect(pm.evaluate({ toolName: 'task' })).toBe('default');
+      expect(pm.evaluate({ toolName: 'agent' })).toBe('default');
     });
 
     it('deny takes precedence over ask and allow', () => {
@@ -1294,8 +1302,8 @@ describe('getRuleDisplayName', () => {
     expect(getRuleDisplayName('web_fetch')).toBe('WebFetch');
   });
 
-  it('maps task to "Task" and skill to "Skill"', () => {
-    expect(getRuleDisplayName('task')).toBe('Task');
+  it('maps agent to "Agent" and skill to "Skill"', () => {
+    expect(getRuleDisplayName('agent')).toBe('Agent');
     expect(getRuleDisplayName('skill')).toBe('Skill');
   });
 
@@ -1488,12 +1496,12 @@ describe('buildPermissionRules', () => {
       expect(rules).toEqual(['Skill(Explore)']);
     });
 
-    it('generates Task rule with specifier', () => {
+    it('generates Agent rule with specifier', () => {
       const rules = buildPermissionRules({
-        toolName: 'task',
+        toolName: 'agent',
         specifier: 'research',
       });
-      expect(rules).toEqual(['Task(research)']);
+      expect(rules).toEqual(['Agent(research)']);
     });
 
     it('falls back to bare display name when no specifier', () => {

packages/core/src/permissions/rule-parser.ts

@@ -99,10 +99,15 @@ export const TOOL_NAME_ALIASES: Readonly<Record<string, string>> = {
   WebSearch: 'web_search',
   WebSearchTool: 'web_search',
 
-  // Task tool
-  task: 'task',
-  Task: 'task',
-  TaskTool: 'task',
+  // Agent (subagent) tool
+  agent: 'agent',
+  Agent: 'agent',
+  AgentTool: 'agent',
+
+  // Legacy aliases for the agent tool (renamed from "task")
+  task: 'agent',
+  Task: 'agent',
+  TaskTool: 'agent',
 
   // Skill tool
   skill: 'skill',
@@ -121,10 +126,6 @@ export const TOOL_NAME_ALIASES: Readonly<Record<string, string>> = {
 
   // Legacy edit tool name
   replace: 'edit',
-
-  // Agent (subagent) rules — "Agent" is a user-friendly alias for the Task tool.
-  // "Agent(Explore)" is parsed with toolName = "task" and specifier = "Explore"
-  Agent: 'task',
 };
 
 /**
@@ -301,7 +302,7 @@ const CANONICAL_TO_RULE_DISPLAY: Readonly<Record<string, string>> = {
   web_fetch: 'WebFetch',
   web_search: 'WebSearch',
   // Agent / Skill
-  task: 'Task',
+  agent: 'Agent',
   skill: 'Skill',
   // Others
   save_memory: 'SaveMemory',

packages/core/src/tools/agent.ts

@@ -534,7 +534,7 @@ class AgentToolInvocation extends BaseToolInvocation<AgentParams, ToolResult> {
           }
         } catch (hookError) {
           debugLogger.warn(
-            `[TaskTool] SubagentStart hook failed, continuing execution: ${hookError}`,
+            `[Agent] SubagentStart hook failed, continuing execution: ${hookError}`,
           );
         }
       }