appstream-generator ignores NoDisplay=true files but it should probably also ignore Hidden=true files which hides it from application menus. If it's not in an app menu it's unlikely to be interesting to software managers.

e.g. https://cgit.kde.org/kaddressbook.git/tree/src/data/kaddressbook-importer.desktop?id=4577f0e7e2ab374b592b39a770ed5d5456821a20