Find fault with completely pointless piece by Keats (4,2)
I believe the answer is:
pick at
'find fault with' is the definition.
(synonyms)
'completely pointless piece by keats' is the wordplay.
I cannot quite understand how this works, but
'piece' could be 'pick' (synonyms) and 'pick' is found within the answer.
'by' could be 'at' and 'at' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for pick at that I've seen before include "Toy with" , "hardly scoff" , "Criticise pettily" , "Nigglingly criticise" , "Carp about" .)