I've put up a simple PoC PR adding a __field_doc__ optional dict attr to dataclass, which would add the docs to class docstring:

@dataclass
class A:
    __field_doc__ = dict(num='number of widgets', total='total widgets')
    total: int
    num: int = 5
print(A.__doc__)

OUTPUT
---

A(total: int, num: int = 5)

num: int [5] -- number of widgets

total: int  -- total widgets