Succinct agreement that's put into handbag (7)
I believe the answer is:
compact
I believe this is a triple definition!
'succinct' is the first definition.
('compact' can be a synonym of 'succinct')
'agreement' is the second definition.
(compact is a kind of agreement)
'that's put into handbag' is the third definition.
(compact mirror)
(Other definitions for compact that I've seen before include "Compress; agreement" , "Small or closely grouped" , "Mutual agreement" , "Neatly packed" , "Agreement - brief" .)