How to add description in FastApi Using Pydantic Model [duplicate]

I'm trying to create a separate class with search parameters that occur in different routers in my application. When I add them to the class, the description does not appear in openapi

I created a separate class with parameters

from fastapi import Query, HTTPException


class PaginatedParams(BaseModel):
    page: Annotated[int, Query(1, description='Page number')]
    size: Annotated[int, Query(10, description='Number of records per page')]

    def validate(self):
        if self.page < 1:
            raise HTTPException(
                status_code=HTTPStatus.BAD_REQUEST,
                detail="Page number must be greater than 0",
            )
        if self.size < 1:
            raise HTTPException(
                status_code=HTTPStatus.BAD_REQUEST,
                detail="Size number must be greater than 0",
            )

Then I added my class to router

from fastapi import APIRouter, Depends, HTTPException, Query


@router.get(
    '/search',
    response_model=dict[str, list[FilmsListApi] | int | str],
    description='Search films by its title.',
)
async def search_films(
        params: PaginatedParams = Depends(PaginatedParams),
        query: str = Query('', description='The keywords for searching films'),
        film_service: FilmService = Depends(get_film_service),
) -> dict[str, list[FilmsListApi] | int | str]:

And I expected that at the api/openapi address the description of the parameters would be displayed in the same way as the query, but this does not happen

enter image description here

I tried changing the code in various ways but couldn't achieve anything. I think that the problem may lie in some place that I may not know about.