Rescind brief authority (5)
I believe the answer is:
remit
I believe this clue is a triple definition!
'rescind' is the first definition.
'brief' is the second definition.
(both can mean someone's responsibilities)
'authority' is the third definition.
(I've seen this before)
(Other definitions for remit that I've seen before include "Orders" , "Scope - send money" , "Timer (anag.)" , "forward" , "Shorten sentence or send money" .)