[LiteLlm] Google tool crash if we use llmproxy pointing to gemini 2.x models

[pretbc]

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Contribution guide.

Describe the bug
gemini models from Litellm via llmproxy cannot use google search tool

due to parser:

def extract_model_name(model_string: str) -> str:
  """Extract the actual model name from either simple or path-based format.

  Args:
    model_string: Either a simple model name like "gemini-2.5-pro" or
                  a path-based model name like "projects/.../models/gemini-2.0-flash-001"

  Returns:
    The extracted model name (e.g., "gemini-2.5-pro")
  """
  # Pattern for path-based model names
  path_pattern = (
      r'^projects/[^/]+/locations/[^/]+/publishers/[^/]+/models/(.+)$'
  )
  match = re.match(path_pattern, model_string)
  if match:
    return match.group(1)

  # If it's not a path-based model, return as-is (simple model name)
  return model_string

logs

/google/adk/tools/google_search_tool.py", line 64, in process_llm_request
    raise ValueError(
        f'Google search tool is not supported for model {llm_request.model}'
    )
ValueError: Google search tool is not supported for model litellm_proxy/vertex_ai/gemini-2.0-flash
ERROR:a2a.server.apps.jsonrpc.jsonrpc_app:Request Error (ID: e8992a46-18c1-4d5e-acaf-1000572f3940): Code=-32603, Message='Google search tool is not supported for model litellm_proxy/vertex_ai/gemini-2.0-flash'

To Reproduce

1. create LLMAgent Object using model = LiteLlm(model="litellm_proxy/vertex_ai/gemini-2.0-flash")
2. Add google search as tool
3. Run and ask model to search..

Expected behavior
It is gemini model, it should work

Desktop (please complete the following information):

• OS: Mac
• Python version(python -V): 13.3
• ADK version(pip show google-adk): 1.8.0

Model Information:
litellm_proxy/vertex_ai/gemini-2.0-flash

Additional context
Add any other context about the problem here.

[llalitkumarrr]

Hello @pretbc

Could you try our latest ADK version to see if your issue is resolved or not?