I've been told here and there that the "description" is important for SEO purposes and it's an optional, but should be filled in, attribute on WordPress when inserting an image.
I never ever fill this in and, to test, just now I inserted an image in the blank WordPress theme I use for testing plugins etc. (on local) and, obviously the "alt" has to be filled in since it's required, the "title" tag is optional but good to put in. Both show up in the code but, unless I'm missing something, "description" does not.
My question is simply, is this true? Is it needed?