fix(core): prevent redundant remote agent loading on model switch (#23576)

packages/core/src/agents/registry.test.ts

@@ -1206,6 +1206,32 @@ describe('AgentRegistry', () => {
   });
 
   describe('inheritance and refresh', () => {
+    it('should skip remote agents when refreshing on model change', async () => {
+      const remoteAgent: AgentDefinition = {
+        kind: 'remote',
+        name: 'RemoteAgent',
+        description: 'A remote agent',
+        agentCardUrl: 'https://example.com/card',
+        inputConfig: { inputSchema: { type: 'object' } },
+      };
+
+      const loadAgentSpy = vi.fn().mockResolvedValue({ name: 'RemoteAgent' });
+      vi.spyOn(mockConfig, 'getA2AClientManager').mockReturnValue({
+        loadAgent: loadAgentSpy,
+        clearCache: vi.fn(),
+      } as unknown as A2AClientManager);
+
+      await registry.testRegisterAgent(remoteAgent);
+
+      expect(loadAgentSpy).toHaveBeenCalledTimes(1);
+
+      coreEvents.emitModelChanged('new-model');
+
+      await new Promise((resolve) => setTimeout(resolve, 0));
+
+      expect(loadAgentSpy).toHaveBeenCalledTimes(1);
+    });
+
     it('should resolve "inherit" to the current model from configuration', async () => {
       const config = makeMockedConfig({ model: 'current-model' });
       const registry = new TestableAgentRegistry(config);

packages/core/src/agents/registry.ts

@@ -57,7 +57,7 @@ export class AgentRegistry {
   }
 
   private onModelChanged = () => {
-    this.refreshAgents().catch((e) => {
+    this.refreshAgents('local').catch((e) => {
       debugLogger.error(
         '[AgentRegistry] Failed to refresh agents on model change:',
         e,
@@ -270,12 +270,16 @@ export class AgentRegistry {
     }
   }
 
-  private async refreshAgents(): Promise<void> {
+  private async refreshAgents(
+    scope: AgentDefinition['kind'] | 'all' = 'all',
+  ): Promise<void> {
     this.loadBuiltInAgents();
     await Promise.allSettled(
-      Array.from(this.agents.values()).map((agent) =>
-        this.registerAgent(agent),
-      ),
+      Array.from(this.agents.values()).map(async (agent) => {
+        if (scope === 'all' || agent.kind === scope) {
+          await this.registerAgent(agent);
+        }
+      }),
     );
   }