microsoft/autogen · error · ValueError

Strict mode is enabled but additional argument is also enabl

Error message

Strict mode is enabled but additional argument is also enabled. This is not allowed in strict mode.

What it means

Error "Strict mode is enabled but additional argument is also enabled. This is not allowed in strict mode." thrown in microsoft/autogen.

Source

Thrown at python/packages/autogen-core/src/autogen_core/tools/_base.py:138

            del model_schema["$defs"]

        parameters = ParametersSchema(
            type="object",
            properties=model_schema["properties"],
            required=model_schema.get("required", []),
            additionalProperties=model_schema.get("additionalProperties", False),
        )

        # If strict is enabled, the tool schema should list all properties as required.
        assert "required" in parameters
        if self._strict and set(parameters["required"]) != set(parameters["properties"].keys()):
            raise ValueError(
                "Strict mode is enabled, but not all input arguments are marked as required. Default arguments are not allowed in strict mode."
            )

        assert "additionalProperties" in parameters
        if self._strict and parameters["additionalProperties"]:
            raise ValueError(
                "Strict mode is enabled but additional argument is also enabled. This is not allowed in strict mode."
            )

        tool_schema = ToolSchema(
            name=self._name,
            description=self._description,
            parameters=parameters,
            strict=self._strict,
        )
        return tool_schema

    @property
    def name(self) -> str:
        return self._name

    @property
    def description(self) -> str:
        return self._description

View on GitHub (pinned to 027ecf0a37)

Solutions

1. Disable additionalProperties when strict mode is on

Example fix

Set strict mode without additional argument allowance

When it happens

Trigger: Thrown at python/packages/autogen-core/src/autogen_core/tools/_base.py:138 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of microsoft/autogen@027ecf0a37 (2026-08-15). Data as JSON: /api/errors/27615eea525eab95. Report an issue: GitHub.