Rowdy hermits — ridiculous! That's clever writing? (12)
I believe the answer is:
'clever writing?' is the definition.
'rowdy hermits ridiculous' is the wordplay.
'ridiculous' indicates an anagram.
'rowdyhermits' with letters rearranged gives 'WORDSMITHERY'.
'that's' is the link.
(Other definitions for wordsmithery that I've seen before include "use of "language"" , "coinage" .)