It's a really good idea to make your posts accessible:

- It helps blind, deaf & deafblind people read your post
- It also helps abled people read your post
- Accessible posts get more boosts

Here's a complete guide with step-by-step instructions and also lots of questions answered about this topic:

https://fedi.tips/how-do-i-make-posts-more-accessible-to-blind-people-on-mastodon-and-the-fediverse

As well as adding descriptions to images etc, there are also lots of things you can do to make text-only posts more accessible too.