Once more assesses setters in need of editing (7)
I believe the answer is:
retests
'once more assesses' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'setters in need of editing' is the wordplay.
'in need of editing' indicates anagramming the letters.
'setters' is an anagram of 'RETESTS'.
Can you help me to learn more?
(Other definitions for retests that I've seen before include "Again investigates" , "further examinations" .)