Merge https://github.com/google/adk-python/pull/3988
### Link to Issue or Description of Change
**1. Link to an existing issue (if applicable):**
- Closes: https://github.com/google/adk-python/issues/3987
- Related: https://github.com/google/adk-python/issues/3596
**2. Or, if no issue exists, describe the change:**
**Problem:**
Idea about my use case
I'm building the report generation system using google-ask (1.18.0) and building multiple subagents here, I'm passing the one subagent Agent as a tool to another Parent Agent. Note: Sub-agent can do web search.
here, parent agent triggers multiple sub-agent (same agent) multiple times according to use case or complexity of the user input
Describe the bug
here, the bug sometimes sub agents doesn't provide the proper output and resulted in the
```
merged_text = '\n'.join(p.text for p in last_content.parts if p.text)
^^^^^^^^^^^^^^^^^^
TypeError: 'NoneType' object is not iterable
and it's breaking the system of Agents workflow
```
**Solution:**
Creating fallback if there is no **last_content.parts** it will return the empty parts so we won't face the NoneType issue
### Testing Plan
Created a unit test file for this issue
test_google_search_agent_tool_repro.py
**Unit Tests:**
- [X] I have added or updated unit tests for my change.
- [X] All unit tests pass locally.
_Please include a summary of passed `pytest` results._
3677 passed, 2208 warnings in 42.64s
**Manual End-to-End (E2E) Tests:**
N/A
### Checklist
- [X] I have read the [CONTRIBUTING.md](https://github.com/google/adk-python/blob/main/CONTRIBUTING.md) document.
- [X] I have performed a self-review of my own code.
- [X] I have commented my code, particularly in hard-to-understand areas.
- [X] I have added tests that prove my fix is effective or that my feature works.
- [X] New and existing unit tests pass locally with my changes.
- [X] I have manually tested my changes end-to-end.
- [ ] Any dependent changes have been merged and published in downstream modules.
### Additional context
N/A
Co-authored-by: Liang Wu <wuliang@google.com>
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/3988 from ananthanarayanan-28:none-type-issue e6ba948345adfc5ac73a5e39d11c68236f117179
PiperOrigin-RevId: 856515019
Merge https://github.com/google/adk-python/pull/3411
## Summary
Fixes AgentTool cleanup to prevent MCP session errors by calling `runner.close()` after sub-agent execution.
## Problem
When using AgentTool with MCP tools, the runner cleanup happened during garbage collection in a different async task context, causing:
```
RuntimeError: Attempted to exit cancel scope in a different task than it was entered in
```
## Solution
- Call `await runner.close()` immediately after sub-agent execution in AgentTool
- This ensures MCP sessions and other resources are cleaned up in the correct async task context
- Updated test mock to include the close() method
## Demo Agents
Added two comprehensive demo agents showing how to use AgentTool with MCP tools:
### mcp_in_agent_tool_remote (SSE mode)
- Uses HTTP/SSE connection to remote MCP server
- Zero-installation setup with `uvx`
- Demonstrates server-side MCP deployment pattern
### mcp_in_agent_tool_stdio (stdio mode)
- Uses subprocess connection with automatic server launch
- Fully automatic setup with `uvx` subdirectory syntax
- Demonstrates embedded MCP deployment pattern
Both demos:
- Use Gemini 2.5 Flash
- Include example prompts for JSON Schema exploration
- Have comprehensive READMEs with architecture diagrams
- Follow ADK agent structure conventions
## Testing
- ✅ All existing unit tests pass
- ✅ Manual testing with both SSE and stdio modes
- ✅ Verified cleanup happens in correct async context
- ✅ No more cancel scope errors with MCP tools
## Related
- Fixes#1112
- Related to #929
Co-authored-by: Wei Sun (Jack) <weisun@google.com>
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/3411 from google:fix/agent-tool-mcp-cleanup 9ae753b5a4
PiperOrigin-RevId: 828651896
- let _enforce_app_name_alignment warn instead of raising while caching the hint that now augments the existing “Session not found …” error
- tighten _infer_agent_origin so it ignores hidden folders (like .venv)
- make AgentTool reuse the parent runner’s app_name, stopping internal runners from conflicting in multi-agent setups
PiperOrigin-RevId: 822205860
* Move unit tests to root package.
* Adds deps to "test" extra, and mark two broken tests in tests/unittests/auth/test_auth_handler.py
* Adds github workflow
* minor fix in lite_llm.py for python 3.9.
* format pyproject.toml
