Note right back is in good shape (4)
I believe the answer is:
trim
'in good shape' is the definition.
(I've seen this in another clue)
'note right back' is the wordplay.
'note' becomes 'mi' (as in do-re-mi).
'right' becomes 'rt' (abbreviation as in Rt Hon- the Right Honourable).
'back' says the letters should be written in reverse.
'mi'+'rt'='mirt'
'mirt' in reverse letter order is 'TRIM'.
'is' acts as a link.
(Other definitions for trim that I've seen before include "Cut away protruding bits, say of hair" , "Tidy; cut" , "Neat - prune" , "in good condition" , "(Make) neat and tidy" .)