Proper to have journalist briefed (6)
I believe the answer is:
primed
'briefed' is the definition.
(I've seen this before)
'proper to have journalist' is the wordplay.
'proper' becomes 'prim' ('prim' can be similar in meaning to 'proper').
'to have' says to put letters next to each other.
'journalist' becomes 'ed' (short for editor).
'prim'+'ed'='PRIMED'
(Other definitions for primed that I've seen before include "Made ready for action" , "Prepared something for use or action" , "Made ready (to fire)" , "Told what to say" , "Loaded or put on a preparatory coating" .)