My summaries tend to be short (2-3 sentences) and from within the story world -- less "Canon-divergent AU where Shuri has to fight Kilmonger because T'Challa is MIA" and more "Shuri thought her estranged cousin killing her brother and taking over her country was a bad as it was going to get. That was before the gods decided to get invested." or something.

I dislike summaries that are quotes from the fic.