hotfix on agentscope_agent (#194)

## Description
hotfix on agentscope_agent

**Related Issue:** Fixes #[issue_number] or Relates to #[issue_number]

**Security Considerations:** [If applicable, especially for sandbox
changes]

## Type of Change
- [x] Bug fix
- [ ] New feature
- [ ] Breaking change
- [ ] Documentation
- [ ] Refactoring

## Component(s) Affected
- [x] Engine
- [ ] Sandbox
- [ ] Documentation
- [ ] Tests
- [ ] CI/CD

## Checklist
- [x] Pre-commit hooks pass
- [x] Tests pass locally
- [x] Documentation updated (if needed)
- [x] Ready for review

## Testing
[How to test these changes]

## Additional Notes
[Optional: any other context]

---------

Co-authored-by: Bruce <godot.lzl@alibaba-inc.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: 3 people

src/agentscope_runtime/engine/agents/agentscope_agent.py

@@ -394,11 +394,15 @@ async def run_async(
                             index = None
 
                         elif element.get("type") == "tool_result":
-                            json_str = json.dumps(element.get("output"))
+                            json_str = json.dumps(
+                                element.get("output"),
+                                ensure_ascii=False,
+                            )
                             data_delta_content = DataContent(
                                 index=index,
                                 data=FunctionCallOutput(
                                     call_id=element.get("id"),
+                                    name=element.get("name"),
                                     output=json_str,
                                 ).model_dump(),
                             )