Agreement at Tyre redrafted (6)
I believe the answer is:
treaty
'agreement' is the definition.
(I know that agreement can be written as treaty)
'at tyre redrafted' is the wordplay.
'redrafted' is an anagram indicator (to redraft something is to improve or rewrite it).
'at'+'tyre'='attyre'
'attyre' is an anagram of 'TREATY'.
(Other definitions for treaty that I've seen before include "Formal pact" , "Negotiation" , "settlement" , "Compact; concordat" , "Pact, accord between states" .)