Barrister should be succinct (5)
I believe the answer is:
brief
I believe this clue is a double definition.
'barrister' is the first definition.
(I've seen this before)
'succinct' is the second definition.
(I've seen this before)
'should be' acts as a link.
(Other definitions for brief that I've seen before include "Barrister (sl.)" , "Prime" , "put in the picture" , "Terse" , "Remit" .)