Agent: is it wrong to be prompt? (9)
I believe the answer is:
instigate
'be prompt?' is the definition.
(I've seen this before)
'agent is it wrong' is the wordplay.
'wrong' is an anagram indicator.
'agent'+'is'+'it'='agentisit'
'agentisit' anagrammed gives 'INSTIGATE'.
'to' is the link.
(Other definitions for instigate that I've seen before include "Bring about by incitement - its eating (anag)" , "Bring about, initiate" , "I taste gin to incite or urge" , "Urge on - teasing it (anag)" , "Incite - set in motion" .)