Agent, not quite penniless (5)
I believe the answer is:
broke
'penniless' is the definition.
(thesaurus)
'agent not quite' is the wordplay.
'agent' becomes 'broker' ('broker' can be a synonym of 'agent').
'not quite' means to remove the last letter.
'broker' with its final letter taken away is 'BROKE'.
(Other definitions for broke that I've seen before include "With completely empty pockets" , "Lacking funds" , "Skint" , "Bust - something to go for?" , "Impecunious" .)