Fix tool output fragmentation by encapsulating content in functionResponse

packages/a2a-server/src/utils/testing_utils.ts

@@ -11,6 +11,7 @@ import type {
 } from '@a2a-js/sdk';
 import {
   ApprovalMode,
+  DEFAULT_GEMINI_MODEL,
   DEFAULT_TRUNCATE_TOOL_OUTPUT_LINES,
   DEFAULT_TRUNCATE_TOOL_OUTPUT_THRESHOLD,
   GeminiClient,
@@ -46,6 +47,7 @@ export function createMockConfig(
     getTruncateToolOutputThreshold: () =>
       DEFAULT_TRUNCATE_TOOL_OUTPUT_THRESHOLD,
     getTruncateToolOutputLines: () => DEFAULT_TRUNCATE_TOOL_OUTPUT_LINES,
+    getActiveModel: vi.fn().mockReturnValue(DEFAULT_GEMINI_MODEL),
     getDebugMode: vi.fn().mockReturnValue(false),
     getContentGeneratorConfig: vi.fn().mockReturnValue({ model: 'gemini-pro' }),
     getModel: vi.fn().mockReturnValue('gemini-pro'),

packages/cli/src/ui/hooks/useToolScheduler.test.ts

@@ -33,6 +33,7 @@ import {
   ApprovalMode,
   MockTool,
   HookSystem,
+  PREVIEW_GEMINI_MODEL,
 } from '@google/gemini-cli-core';
 import { createMockMessageBus } from '@google/gemini-cli-core/src/test-utils/mock-message-bus.js';
 import { ToolCallStatus } from '../types.js';
@@ -71,6 +72,7 @@ const mockConfig = {
   getTruncateToolOutputThreshold: () => DEFAULT_TRUNCATE_TOOL_OUTPUT_THRESHOLD,
   getTruncateToolOutputLines: () => DEFAULT_TRUNCATE_TOOL_OUTPUT_LINES,
   getAllowedTools: vi.fn(() => []),
+  getActiveModel: () => PREVIEW_GEMINI_MODEL,
   getContentGeneratorConfig: () => ({
     model: 'test-model',
     authType: 'oauth-personal',

packages/cli/src/zed-integration/zedIntegration.ts

@@ -497,7 +497,12 @@ export class Session {
         ),
       );
 
-      return convertToFunctionResponse(fc.name, callId, toolResult.llmContent);
+      return convertToFunctionResponse(
+        fc.name,
+        callId,
+        toolResult.llmContent,
+        this.config.getActiveModel(),
+      );
     } catch (e) {
       const error = e instanceof Error ? e : new Error(String(e));
 

packages/core/src/config/models.test.ts

@@ -14,8 +14,25 @@
   GEMINI_MODEL_ALIAS_PRO,
   GEMINI_MODEL_ALIAS_FLASH,
   GEMINI_MODEL_ALIAS_FLASH_LITE,
+  supportsMultimodalFunctionResponse,
 } from './models.js';
 
+describe('supportsMultimodalFunctionResponse', () => {
+  it('should return true for gemini-3 model', () => {
+    expect(supportsMultimodalFunctionResponse('gemini-3-pro')).toBe(true);
+  });
+
+  it('should return false for gemini-2 models', () => {
+    expect(supportsMultimodalFunctionResponse('gemini-2.5-pro')).toBe(false);
+    expect(supportsMultimodalFunctionResponse('gemini-2.5-flash')).toBe(false);
+  });
+
+  it('should return false for other models', () => {
+    expect(supportsMultimodalFunctionResponse('some-other-model')).toBe(false);
+    expect(supportsMultimodalFunctionResponse('')).toBe(false);
+  });
+});
+
 describe('getEffectiveModel', () => {
   describe('When NOT in fallback mode', () => {
     const isInFallbackMode = false;

packages/core/src/config/models.ts

@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
 export const PREVIEW_GEMINI_MODEL = 'gemini-3-pro-preview';
 export const DEFAULT_GEMINI_MODEL = 'gemini-2.5-pro';
 export const DEFAULT_GEMINI_FLASH_MODEL = 'gemini-2.5-flash';
 export const DEFAULT_GEMINI_FLASH_LITE_MODEL = 'gemini-2.5-flash-lite';
@@ -99,8 +99,19 @@
  * Checks if the model is a Gemini 2.x model.
  *
  * @param model The model name to check.
- * @returns True if the model is a Gemini 2.x model.
+ * @returns True if the model is a Gemini-2.x model.
  */
 export function isGemini2Model(model: string): boolean {
   return /^gemini-2(\.|$)/.test(model);
 }
+
+/**
+ * Checks if the model supports multimodal function responses (multimodal data nested within function response).
+ * This is supported in Gemini 3.
+ *
+ * @param model The model name to check.
+ * @returns True if the model supports multimodal function responses.
+ */
+export function supportsMultimodalFunctionResponse(model: string): boolean {
+  return model.startsWith('gemini-3-');
+}