I don't see a problem with that. In particular I don't see it as helping to include sentences that are absolutely the same for all of these.
That is the exact reason why I put it in the general description of the search functions in the documentation.
That is [docs/api.rst](https://github.com/JonnyJD/python-musicbrainz-ngs/blob/20392dbf9ced7146b7d4e0ab0ff0cf033c5b68a1/docs/api.rst) on github and [api#searching](https://python-musicbrainz-ngs-jonnyjd.readthedocs.org/en/doc_changes/api/#searching) on RTFD.

When you are looking at the sphinx documentation, you see the description for the section above and if you don't you should be referred to the documentation. And being referred to the documentation in every docstring is also not a thing that should be put into every docstring, since this is always what you are supposed to do when something is unclear.

Or what would you add to the docstring?