Carpenter should do this to be exactly right (3,3,4,2,3,4)
I believe the answer is:
hit the nail on the head
'carpenter should do this' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'be exactly right' is the wordplay.
I cannot really understand how this works, but
'be' could be 'head' (heading is a kind of being) and 'head' is found in the answer.
'right' could be 'onthe' (synonyms) and 'onthe' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'to' is the link.
Can you help me to learn more?
(Other definitions for hit the nail on the head that I've seen before include "Go straight to the point" , "Get carpentry" , "Get the point? Absolutely not" , "be spot on, anyway" , "Be dead right" .)