diff --git a/packages/core/src/agents/registry.test.ts b/packages/core/src/agents/registry.test.ts
index f57ce9f5d6..7618440957 100644
--- a/packages/core/src/agents/registry.test.ts
+++ b/packages/core/src/agents/registry.test.ts
@@ -1011,57 +1011,44 @@ describe('AgentRegistry', () => {
       );
     });
 
-    it('should override an existing agent but warn on duplicate name', async () => {
+    it('should overwrite an existing agent definition', async () => {
       await registry.testRegisterAgent(MOCK_AGENT_V1);
       expect(registry.getDefinition('MockAgent')?.description).toBe(
         'Mock Description V1',
       );
 
-      const feedbackSpy = vi.spyOn(coreEvents, 'emitFeedback');
       await registry.testRegisterAgent(MOCK_AGENT_V2);
-
-      // Should override to V2 (preserves existing precedence)
       expect(registry.getDefinition('MockAgent')?.description).toBe(
         'Mock Description V2 (Updated)',
       );
       expect(registry.getAllDefinitions()).toHaveLength(1);
-      // But should emit a warning about the duplicate
-      expect(feedbackSpy).toHaveBeenCalledWith(
-        'warning',
-        expect.stringContaining("Duplicate agent name 'MockAgent'"),
-      );
     });
 
-    it('should not warn when re-registering the same definition (refresh)', async () => {
-      await registry.testRegisterAgent(MOCK_AGENT_V1);
-      expect(registry.getDefinition('MockAgent')?.description).toBe(
-        'Mock Description V1',
-      );
-
-      // Re-registering the exact same object should succeed without warning
-      const feedbackSpy = vi.spyOn(coreEvents, 'emitFeedback');
-      await registry.testRegisterAgent(MOCK_AGENT_V1);
-      expect(registry.getDefinition('MockAgent')?.description).toBe(
-        'Mock Description V1',
-      );
-      expect(feedbackSpy).not.toHaveBeenCalledWith(
-        'warning',
-        expect.stringContaining('Duplicate'),
-      );
-    });
-
-    it('should warn on duplicate in debug logs', async () => {
+    it('should log overwrites when in debug mode', async () => {
       const debugConfig = makeMockedConfig({ debugMode: true });
       const debugRegistry = new TestableAgentRegistry(debugConfig);
-      const warnSpy = vi
-        .spyOn(debugLogger, 'warn')
+      const debugLogSpy = vi
+        .spyOn(debugLogger, 'log')
         .mockImplementation(() => {});
 
       await debugRegistry.testRegisterAgent(MOCK_AGENT_V1);
       await debugRegistry.testRegisterAgent(MOCK_AGENT_V2);
 
-      expect(warnSpy).toHaveBeenCalledWith(
-        expect.stringContaining('Overriding agent'),
+      expect(debugLogSpy).toHaveBeenCalledWith(
+        `[AgentRegistry] Overriding agent 'MockAgent'`,
+      );
+    });
+
+    it('should not log overwrites when not in debug mode', async () => {
+      const debugLogSpy = vi
+        .spyOn(debugLogger, 'log')
+        .mockImplementation(() => {});
+
+      await registry.testRegisterAgent(MOCK_AGENT_V1);
+      await registry.testRegisterAgent(MOCK_AGENT_V2);
+
+      expect(debugLogSpy).not.toHaveBeenCalledWith(
+        `[AgentRegistry] Overriding agent 'MockAgent'`,
       );
     });
 
diff --git a/packages/core/src/agents/registry.ts b/packages/core/src/agents/registry.ts
index 45774678ba..b9d434e4c7 100644
--- a/packages/core/src/agents/registry.ts
+++ b/packages/core/src/agents/registry.ts
@@ -328,10 +328,9 @@ export class AgentRegistry {
   }
 
   /**
-   * Registers an agent definition. If an agent with the same name already
-   * exists from a different definition, a warning is emitted to surface
-   * potential state collision. The new definition still overwrites the old
-   * one to preserve existing precedence order (user → project → extension).
+   * Registers an agent definition. If an agent with the same name exists,
+   * it will be overwritten, respecting the precedence established by the
+   * initialization order.
    */
   protected async registerAgent<TOutput extends z.ZodTypeAny>(
     definition: AgentDefinition<TOutput>,