Would it be possible to hack together a usable manual tagging system via the API? I don't mean the automatic face tagging, or built-in tagging functionality (I

Would it be possible to hack together a usable manual tagging system via the API? I don't mean the automatic face tagging, or built-in tagging functionality (I assume Google Photos doesn't have it). I mean would it be possible to use the API to insert keywords into the description fields and reliably search the description fields