When I search for recordings using the search API, each recording's
releases will have their
artist-credit fields populated if the credit is different from the recording's credit (at least that's how I'm guessing it works; this makes sense – no use in cluttering the response with redundant info.)
The remaining releases will have their
artist-credit populated, and this will often be Various Artists. But it looks like after a dozen or so releases, the API just stops including the
artist-credit field, even if it's not the same as the recording.
For example, this search: https://musicbrainz.org/ws/2/recording?query=about%20you%20now%20artist:sugababes
If you find "lovesongs" in that response, you'll note that it doesn't have an
artist-credit. MusicBrainz knows it's Various Artists, and will populate it as such elsewhere via the API. But I think doesn't populate it here because too many previous releases under that same recording had a Various Artists credit already? Is this some kind of optimization that is happening to reduce redundant data in the output? It's making it difficult to conclude whether the releases under each recording are by the artist or not without making a bunch of extra queries.