Relaxed agent does change (7)
I believe the answer is:
reposed
'relaxed' is the definition.
(I've seen this before)
'agent does change' is the wordplay.
'agent' becomes 'rep' (short for representative).
'change' indicates an anagram.
'does' anagrammed gives 'osed'.
'rep'+'osed'='REPOSED'
(Other definitions for reposed that I've seen before include "Rested" , "modelled afresh" , "Relaxed" , "What's settled" .)