We're considering an addition to PEP 681 (dataclass_transform) [1] to better support classes with fields that are descriptors. Setting a new dataclass_transform parameter named "transform_descriptor_types" to True would indicate that __init__ parameters corresponding to descriptor fields have the type of the descriptor's setter value parameter rather than the descriptor type. Here's an example: @dataclass_transform(transform_descriptor_types=True) def decorator() -> Callable[[Type[T]], Type[T]]: ... class Descriptor(Generic[_T]): def __get__(self, instance: object, owner: Any) -> Any: ... def __set__(self, instance: object, value: T | None): ... @decorator class InventoryItem: quantity_on_hand: Descriptor[int] In this case, type checkers would understand that the quantity_on_hand parameter of InventoryItem's __init__ method is of type "int | None" rather than "Descriptor[int]". This change was driven by a need in SQLAlchemy, and we'd appreciate any thoughts on broader applicability. Feedback is welcome either via email or on GitHub! [2] A reference implementation is available in Pyright 1.1.222 and Pylance 2022.2.3. [1] https://www.python.org/dev/peps/pep-0681/ [2] https://github.com/debonte/peps/pull/3/files