The advice from my blind and partially-sighted mutuals is to think how you’d describe it to a friend on a voice call. “Cover of [title], featuring a dragon on a motorbike” could be enough or you might want to add more if it’s relevant - “cover of [title] with the series creator’s name five times larger than the actual author, featuring AI art of a dragon with six and a half fingers on a motorbike with the engine facing backwards”