def test_function_signature_analysis(self, credentials_config):
    """Test that function signature analysis correctly handles credentials parameter.

    The tool should properly identify and handle the credentials parameter
    while preserving other parameter analysis for LLM function calling.
    """

    def complex_function(
        required_param: str,
        optional_param: str = "default",
        credentials: Credentials = None,
    ) -> dict:
      return {"success": True}

    tool = BigQueryTool(
        func=complex_function, credentials_config=credentials_config
    )

    # The 'credentials' parameter should be ignored in mandatory args analysis
    mandatory_args = tool._get_mandatory_args()
    assert "required_param" in mandatory_args
    assert "credentials" not in mandatory_args
    assert "optional_param" not in mandatory_args
Test that function signature analysis correctly handles credentials parameter.

    The tool should properly identify and handle the credentials parameter
    while preserving other parameter analysis for LLM function calling.
    
tests/unittests/tools/bigquery/test_bigquery_tool.py