Through some oversight on my part, when you do

from pydantic import BaseModel

class A(BaseModel):
   a: int
   """Integer counting a"""

the docstring for A.a does not get used to populate the JSONSchema. I think I used to do this with the pydantic_settings package, which has sinced removed the feature, and apparently this will be implemented proper in pydantic v2. But for now we have no descriptions in our schema, unless we explicitly do Field(description=...).