LlmAgent rejects temperature= with extra_forbidden — no discoverable path to generate_content_config

[CarSanoja]

Summary

Coming from google-genai (where GenerateContentConfig(temperature=...) is routine), the natural first attempt with ADK is:

from google.adk.agents import LlmAgent

agent = LlmAgent(
    name="grader",
    model="gemini-3.5-flash-lite",
    instruction="...",
    output_schema=MySchema,
    temperature=0.1,
)

On ADK 2.7.0 this fails at construction time:

pydantic_core._pydantic_core.ValidationError: 1 validation error for LlmAgent temperature Extra inputs are not permitted [type=extra_forbidden, input_value=0.1, input_type=float]

The working form is generate_content_config=genai_types.GenerateContentConfig(temperature=0.1), but nothing in the error, the docstring, or the validation message points there. In our project this crashed every structured agent in a production pipeline and cost a debugging session to trace (model_fields introspection).

Suggested fixes (any one would do)

1. Accept temperature as a convenience kwarg and fold it into generate_content_config.
2. Or add a custom pydantic error message for common generation kwargs (temperature, top_p, max_output_tokens) pointing to generate_content_config.
3. Or document the mapping prominently in the LlmAgent docstring.

Environment

google-adk 2.7.0, google-genai 2.18.1, Python 3.13, macOS. Found while building a K-12 exam-grading fleet for the All Things Agentic hackathon.

[a2105z]

Taking this right now, don't duplicate.

[sanketpatil06]

Hi @CarSanoja, thanks for reporting this. We were able to observe the same behavior you described.
We see that PR #6837 is already open to address this. Could you please confirm if it resolves the issue on your end before we proceed with reviewing and merging it?