from pydantic import BaseModel, Field


class SubQuestions(BaseModel):
    """Structured output model for query decomposition.

    Used with LangChain's with_structured_output() to guarantee
    the LLM returns a valid list of sub-questions.
    """

    questions: list[str] = Field(
        description="2-5 simplified sub-questions, each focused on one aspect",
        min_length=1,
        max_length=5,
    )