This looks great, good work! 👏 Have you consider naming the button "Add Alt Text" or "Add Alternative Text" instead of "Add Accessibility Description"? Here are three reasons you might want to do that:
- Familiarity. Folks coming from other platforms and tools might already be familiar with alt texts. WordPress, Medium, and Instagram, for example, use this naming convention. Users will immediately know what it is, instead of having to ask themselves "I wonder if Accessibility Description is the same as Alt Text?"
- Findability. For someone totally new to the concept of alternative texts, they will get a lot more relevant hits, guides, YouTube videos, and what not when researching "alt text" compared to "accessibility description".
- Nitpicking. 😊 It really is a alternative text. Accessibility is a huge aspect of it, for sure. But the alternative text is also displayed when a browser can't load images (for network reasons or user preference). Also, search engines often index alternative text to deliver better search results. (It's an upcoming feature to my Search Space plug-in.)