I know it's been brought up at least several times before, but beyond general "shouldn't be too big" comments, I couldn't find anything about guidelines for what to do with overly long descriptions.

The one that triggered this question is the description for freefall, which while not a copy/paste of Wikipedia (which doesn't even have an article on FF any more, after it was pulled for a lack of notability) is still much more needed than to describe the comic. Likewise, the entry for the main character florence_ambrose is similarly ridiculously long.

What details to describe a work or character in that work are important, and which can be cut as textual wanking?

I'd just make a synopsis at the top and throw the rest into a section below it labeled "Some more information".