mcp in Interactions API doesnt work.

#### Environment details

- Programming language: Python
- OS: Linux in Colab and Windows 11
- Language runtime version: 3.13
- Package version: 1.65.0

#### Steps to reproduce

1. create a client
2. run the code below

```python
interaction = client.interactions.create(
model="gemini-2.5-flash",
input="what's the weather in Taipei？",
tools = [{
"type": "mcp_server",
"name": "weather_service",
"url": "https://gemini-api-demos.uc.r.appspot.com/mcp"
}]
)
```

this get the following error

```
InternalServerError: Error code: 500 - {'error': {'message': 'Internal server error', 'code': 'api_error'}}
```