A super ending for poems does no good at all! (6)
I believe the answer is:
erodes
'a super ending for poems' is the definition.
I can't tell whether this defines the answer.
'does no good at all' is the wordplay.
'no good' indicates anagramming the letters (no good can mean faulty or defective).
'at' is a charade indicator (letters next to each other) (I've seen this in other clues).
'all' becomes 'er' (I can't explain this - if you can you should give a lot more credence to this answer).
'does' with letters rearranged gives 'odes'.
'odes' after 'er' is 'ERODES'.
Can you help me to learn more?
(Other definitions for erodes that I've seen before include "Wears away with weather" , "Wears away as by time or water" , "Eats away" .)