feat(core): enable team-aware orchestration in top-level agent

- Update SystemPromptOptions to include activeTeam
- Implement renderActiveTeam snippet for team instructions injection
- Update PromptProvider to pass activeTeam from config to system prompt
- Enhance SubagentTool to support description overrides
- Update Config to prioritize and label team-based subagent tools
- Ensure synchronized team reload in TeamRegistry and Config
- Add unit tests for team-aware prompt generation

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

@@ -33,6 +33,7 @@ export class SubagentTool extends BaseDeclarativeTool<AgentInputs, ToolResult> {
     private readonly definition: AgentDefinition,
     private readonly context: AgentLoopContext,
     messageBus: MessageBus,
+    descriptionOverride?: string,
   ) {
     const inputSchema = definition.inputConfig.inputSchema;
 
@@ -47,7 +48,7 @@ export class SubagentTool extends BaseDeclarativeTool<AgentInputs, ToolResult> {
     super(
       definition.name,
       definition.displayName ?? definition.name,
-      definition.description,
+      descriptionOverride ?? definition.description,
       Kind.Agent,
       inputSchema,
       messageBus,

packages/core/src/agents/teamRegistry.ts

@@ -48,7 +48,7 @@ export class TeamRegistry {
     // Load user-level teams first
     const userTeamsDir = Storage.getUserTeamsDir();
     const userLoadResult = await loadTeamsFromDirectory(userTeamsDir);
-    this.processLoadResult(userLoadResult);
+    await this.processLoadResult(userLoadResult);
 
     const folderTrustEnabled = this.config.getFolderTrust();
     const isTrustedFolder = this.config.isTrustedFolder();
@@ -65,7 +65,7 @@ export class TeamRegistry {
       // Load project-level teams (takes precedence over user-level if names collide)
       const projectTeamsDir = this.config.storage.getProjectTeamsDir();
       const projectLoadResult = await loadTeamsFromDirectory(projectTeamsDir);
-      this.processLoadResult(projectLoadResult);
+      await this.processLoadResult(projectLoadResult);
     }
 
     if (this.config.getDebugMode()) {
@@ -73,29 +73,35 @@ export class TeamRegistry {
     }
   }
 
-  private processLoadResult(result: TeamLoadResult): void {
+  private async processLoadResult(result: TeamLoadResult): Promise<void> {
     for (const error of result.errors) {
       debugLogger.warn(`[TeamRegistry] Error loading team: ${error.message}`);
       coreEvents.emitFeedback('error', `Team loading error: ${error.message}`);
     }
 
+    const registrationPromises: Array<Promise<void>> = [];
+
     for (const team of result.teams) {
       this.teams.set(team.name, team);
 
       // Register team agents in the global AgentRegistry so they are available as SubagentTools
       for (const agent of team.agents) {
-        this.agentRegistry.registerAgent(agent).catch((e) => {
-          debugLogger.warn(
-            `[TeamRegistry] Error registering agent "${agent.name}" from team "${team.name}":`,
-            e,
-          );
-          coreEvents.emitFeedback(
-            'error',
-            `Error registering agent "${agent.name}" from team "${team.name}": ${e instanceof Error ? e.message : String(e)}`,
-          );
-        });
+        registrationPromises.push(
+          this.agentRegistry.registerAgent(agent).catch((e) => {
+            debugLogger.warn(
+              `[TeamRegistry] Error registering agent "${agent.name}" from team "${team.name}":`,
+              e,
+            );
+            coreEvents.emitFeedback(
+              'error',
+              `Error registering agent "${agent.name}" from team "${team.name}": ${e instanceof Error ? e.message : String(e)}`,
+            );
+          }),
+        );
       }
     }
+
+    await Promise.allSettled(registrationPromises);
   }
 
   /**

packages/core/src/config/config.ts

@@ -3617,6 +3617,9 @@ export class Config implements McpContext, AgentLoopContext {
     }
 
     const discoveredNames = this.agentRegistry.getAllDiscoveredAgentNames();
+    const activeTeam = this.teamRegistry.getActiveTeam();
+    const teamAgentNames = new Set(activeTeam?.agents.map((a) => a.name) ?? []);
+
     for (const agentName of discoveredNames) {
       const definition = this.agentRegistry.getDiscoveredDefinition(agentName);
       if (!definition) {
@@ -3630,7 +3633,17 @@ export class Config implements McpContext, AgentLoopContext {
           continue;
         }
 
-        const tool = new SubagentTool(definition, this, this.messageBus);
+        let descriptionOverride = definition.description;
+        if (teamAgentNames.has(definition.name)) {
+          descriptionOverride = `(Team Agent: ${activeTeam?.displayName}) ${definition.description}`;
+        }
+
+        const tool = new SubagentTool(
+          definition,
+          this,
+          this.messageBus,
+          descriptionOverride,
+        );
         registry.registerTool(tool);
       } catch (e: unknown) {
         debugLogger.warn(
@@ -3730,8 +3743,10 @@ export class Config implements McpContext, AgentLoopContext {
   }
 
   private onAgentsRefreshed = async () => {
+    debugLogger.log('[Config] onAgentsRefreshed triggered');
     await this.teamRegistry.reload();
     if (this._toolRegistry) {
+      debugLogger.log('[Config] Re-registering sub-agent tools');
       this.registerSubAgentTools(this._toolRegistry);
     }
     // Propagate updates to the active chat session

packages/core/src/prompts/promptProvider-teams.test.ts

@@ -0,0 +1,78 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { PromptProvider } from './promptProvider.js';
+import { type AgentLoopContext } from '../config/agent-loop-context.js';
+import { type TeamDefinition } from '../agents/types.js';
+
+describe('PromptProvider with Agent Teams', () => {
+  let promptProvider: PromptProvider;
+  let mockContext: AgentLoopContext;
+
+  beforeEach(() => {
+    promptProvider = new PromptProvider();
+    mockContext = {
+      config: {
+        isInteractive: vi.fn().mockReturnValue(true),
+        getSkillManager: vi.fn().mockReturnValue({ getSkills: () => [] }),
+        getAgentRegistry: vi
+          .fn()
+          .mockReturnValue({ getAllDefinitions: () => [] }),
+        getActiveModel: vi.fn().mockReturnValue('gemini-3.1-pro-preview'),
+        getActiveTeam: vi.fn().mockReturnValue(undefined),
+        getApprovedPlanPath: vi.fn().mockReturnValue(undefined),
+        getApprovalMode: vi.fn().mockReturnValue('default'),
+        getGemini31LaunchedSync: vi.fn().mockReturnValue(true),
+        getGemini31FlashLiteLaunchedSync: vi.fn().mockReturnValue(true),
+        getHasAccessToPreviewModel: vi.fn().mockReturnValue(true),
+        isTrackerEnabled: vi.fn().mockReturnValue(false),
+        isTopicUpdateNarrationEnabled: vi.fn().mockReturnValue(false),
+        isMemoryManagerEnabled: vi.fn().mockReturnValue(false),
+        isInteractiveShellEnabled: vi.fn().mockReturnValue(true),
+        getEnableShellOutputEfficiency: vi.fn().mockReturnValue(true),
+        getSandboxEnabled: vi.fn().mockReturnValue(false),
+        storage: {
+          getPlansDir: vi.fn().mockReturnValue('/tmp/plans'),
+        },
+        topicState: {
+          getTopic: vi.fn().mockReturnValue(undefined),
+        },
+      },
+      toolRegistry: {
+        getAllToolNames: vi.fn().mockReturnValue([]),
+        getAllTools: vi.fn().mockReturnValue([]),
+      },
+    } as unknown as AgentLoopContext;
+  });
+
+  it('should not include team section when no team is active', () => {
+    const prompt = promptProvider.getCoreSystemPrompt(
+      mockContext as unknown as AgentLoopContext,
+    );
+    expect(prompt).not.toContain('# Active Agent Team');
+  });
+
+  it('should include team section when a team is active', () => {
+    const mockTeam: TeamDefinition = {
+      name: 'test-team',
+      displayName: 'Test Team',
+      description: 'A test team',
+      instructions: 'These are the team instructions.',
+      agents: [],
+    };
+    mockContext.config.getActiveTeam.mockReturnValue(mockTeam);
+
+    const prompt = promptProvider.getCoreSystemPrompt(
+      mockContext as unknown as AgentLoopContext,
+    );
+    expect(prompt).toContain('# Active Agent Team: Test Team');
+    expect(prompt).toContain('These are the team instructions.');
+    expect(prompt).toContain(
+      "You should prioritize delegating tasks to this team's agents whenever appropriate.",
+    );
+  });
+});

packages/core/src/prompts/promptProvider.ts

@@ -140,6 +140,7 @@ export class PromptProvider {
           contextFilenames,
           topicUpdateNarration: context.config.isTopicUpdateNarrationEnabled(),
         })),
+        activeTeam: context.config.getActiveTeam(),
         subAgents: this.withSection('agentContexts', () =>
           context.config
             .getAgentRegistry()

packages/core/src/prompts/snippets.ts

@@ -36,12 +36,14 @@ import {
 } from '../tools/tool-names.js';
 import type { HierarchicalMemory } from '../config/memory.js';
 import { DEFAULT_CONTEXT_FILENAME } from '../tools/memoryTool.js';
+import { type TeamDefinition } from '../agents/types.js';
 
 // --- Options Structs ---
 
 export interface SystemPromptOptions {
   preamble?: PreambleOptions;
   coreMandates?: CoreMandatesOptions;
+  activeTeam?: TeamDefinition;
   subAgents?: SubAgentOptions[];
   agentSkills?: AgentSkillOptions[];
   hookContext?: boolean;
@@ -126,6 +128,8 @@ ${renderPreamble(options.preamble)}
 
 ${renderCoreMandates(options.coreMandates)}
 
+${renderActiveTeam(options.activeTeam)}
+
 ${renderSubAgents(options.subAgents)}
 
 ${renderAgentSkills(options.agentSkills)}
@@ -247,6 +251,16 @@ Use the following guidelines to optimize your search and read patterns.
 `.trim();
 }
 
+export function renderActiveTeam(team?: TeamDefinition): string {
+  if (!team) return '';
+  return `
+# Active Agent Team: ${team.displayName}
+
+${team.instructions}
+
+You should prioritize delegating tasks to this team's agents whenever appropriate.`.trim();
+}
+
 export function renderSubAgents(subAgents?: SubAgentOptions[]): string {
   if (!subAgents || subAgents.length === 0) return '';
   const subAgentsXml = subAgents