I'm seeing a lot of proclamations that there should be no exceptions to describing your images or that there's no reason to interact with any that aren't described.
I know these mean well, but they are themselves ableist.
Disabled people know that access needs can clash. I benefit from described images, but I know some people struggle to write them because of their own disabilities.
And that's okay! The culture of image descriptions is great here but it should never be absolutist.
I challenged someone on their hardline stance on this once, and it blew up into a tiny fedi drama, with the nice outcome of more social solutions.
That's around the time people started to CW undescribed images.
My instance developed an emoji 
to indicate you'd like a media description added.
There's a group you can tag, @imagecaptionspls, that people follow who are willing to add descriptions.
And there's @PleaseCaption to remind you if you forget.
Since I first wrote this, a good cultural norm that has found its way to fedi is the hashtags Alt4Me (where you can ask for an image description) and Alt4You (where you can add one to a toot that lacks it).
Also, most instances have edit functionality now, which makes it really easy to add the image description back into your toot if someone adds one for you!
@niki Oh is that not a mainline thing? Heck. My instance uses Hometown and I can't keep track of what is a feature of what.
Back before editing image descriptions was possible, though, the received wisdom seemed to be that if you removed and then re-uploaded the photo, you could add the description then. That still doesn't seem overly difficult, as general advice goes.
@bright_helpings @niki Caption editing is on mainline since Feb 2023.
NIST Standard Reference Boy
mice go meow 
clacke: exhausted pixie dream boy 🇸🇪🇭🇰💙💛
Dr Ro Smith