Docs via Python code

The aiohttp-apispec tool uses a wrapper to create the presentation documentation.

@docs(
    summary="Test method summary",
    description="Test method description",
    responses={
        200: {
            "schema": ResponseSchema,
            "description": "Success response",
        },
    },
)
async def index(request):
    return web.json_response({"msg": "done", "data": {}})

Is there any reason why you didn't do the same?
Seems to me it's simpler and gives less errors.

Start by comparing the current presentation-documentation wrapper with the aiohttp-apispec @docs example quoted in the issue. Determine whether adopting that style is a defined, testable change; done should be an agreed scope with the relevant documentation or implementation work identified.