Okay, Kid3 maps their “Description” tag to the ID3 specification’s TIT3, or Title3 tag. Per the ID3 spec, this tag is supposed to be for:
The ‘Subtitle/Description refinement’ frame is used for information
directly related to the contents title (e.g. “Op. 16” or “Performed
live at Wembley”).
So I don’t think it’s intended for the comments about the book that you’re looking for.
But the other problem is that Plex currently does not import the TIT3 tag at all, so it wouldn’t solve your issue anyway. It is one of several tags that we are hoping will be added.
