I cannot reproduce on my end; it is generating as expected. Are you perhaps using stop keywords as defined by your database driver in the description?

Pretty much a clean install, works on gallery content but not on categories (localhost install). No big deal just something I noticed.

"from gallery video description" seems to contradict "works on gallery content but not on categories" so I suspect there's a typo in this issue title.

Regardless, I cannot reproduce either. I tried adding a gallery, an image, and a video, and meta tags were generated in all cases.

Note auto-generation will only work for newly added content, not editing existing content. It is also subject to Composr's stopword list (text/EN/too_common_words.txt).

Apologies, I meant "from gallery category description".