Name included in benefit agreement (6)
I believe the answer is:
assent
'agreement' is the definition.
(I know that assent is a type of agreement)
'name included in benefit' is the wordplay.
'name' becomes 'n' (common abbreviation e.g. on forms).
'included in' indicates putting letters inside.
'benefit' becomes 'asset' (I've seen this in another clue).
'n' put inside 'asset' is 'ASSENT'.
(Other definitions for assent that I've seen before include "Give the thumbs-up" , "Give consent" , "Acquiesce, comply" , "Permission" , "Accede, agree" .)