alt text is better when it does not assume niche knowledge
I'm guilty of this! when I was #spindleposting it took me a fair minute to realize I was just saying "drop spindle" in the alt text without explaining what the hell a drop spindle looked like.
insert xkcd experts comic here
same with like, birds, I always try to describe the bird. don't just say it's name, because plenty of people don't know it by name
unless maybe it's a seagull or crow or something really common. then I slack.