I'm seeing a huge uptick in fanart with artist-written alt text and IDs in my fandom circles recently, which is obviously great! But I can also tell that a lot of people, because they're just getting started, haven't quite figured out how to consider the screen reader experience while writing alt text/IDs.
The remedy to this, when in doubt, is to pull up a screen reader or TTS on your own device. That way, you can hear out how things sound. But in general, a couple things to keep in mind:
For multi-image posts: You don't have to repeat the same information in the description of every single image.
If you have a four-image comic, and a character — let's just say a young adult white woman, with brown hair and glasses — features in all those panels, you don't have to repeat that description in every ALT text. The images are going to be read in order, and in context. If a screen reader has to hear "a young adult white woman, with brown hair and glasses" four separate times in quick succession, to say nothing of other recurring characters, that's not a good listening experience!
Yes, if you were to share one of those panels on its own, in some other instance, it might be good to slightly edit the image description, and actually re-include that information. The description of an image is always going to be influenced by the purpose and context of an image — just like images being shared to appreciate the artistry will warrant more description than IDs for memes, where it's best to keep things brief. (And on that topic, this post puts it better than I could.)
In-post image descriptions should go directly under the image. There should not be commentary in-between the image and the ID.
Imagine if every time you wanted to know what an image was, whether a piece of art or a screenshot of a tweet, you had to hear paragraphs of the artist's statement that presumed you'd seen the art already, or paragraphs of OP's commentary lampooning the tweeter. Imagine if every time anyone posted a graph, you had to read through a short essay presuming you'd seen the graph, but before you actually got to see what the graph was showing.
Yeah, that's the essence of the problem with putting IDs below commentary.
Also, after a point, people will just assume the post is undescribed and skip it! You described your post, you put in the effort to make your post accessible, but you want to make sure it'll have the impact you hope it will, right? Hiding the ID below commentary (or under a read more) is not going to let your effort have the maximum impact.
Here's a visual example of the formatting guideline I just described.
In general, there are many elements of writing IDs that are just subjective, and there are many ID beneficiaries whose preferences differ amongst each other, too. But if you start out by not including redundant information, by considering context, and by considering flow for screen readers? Then you're starting out totally fine.