With Moist, Pratchett manages a neat trick. All of the other characters (save the villainous Lavishes) comment on how charming and resourceful he is, and then Pratchett makes him appear charming and resourceful to us as well. This is no small feat; it’s like a ballplayer pointing to a section of the bleachers before knocking the next pitch there. Writing is supposedly about showing, not telling, and Pratchett has gone ahead and done both.
(Thanks to Jenny Davidson for this.)