Raw JSON schema dicts are not validated
When schema is a raw JSON schema dict (as opposed to a Pydantic model,
dataclass, or TypedDict), the model's tool-call arguments are returned
as-is without validation against the schema.
As a result, handle_errors is effectively inert for dict schemas. To get
validation and automatic retries, express the schema as a Pydantic model,
dataclass, or TypedDict instead.
