Agreements showing restrictions about different rate (8)
I believe the answer is:
treaties
'agreements' is the definition.
(I know this)
'restrictions about different rate' is the wordplay.
'restrictions' becomes 'ties'.
'about' means one lot of letters goes inside another.
'different' indicates anagramming the letters (letters placed in a different order).
'rate' anagrammed gives 'reat'.
'ties' going around 'reat' is 'TREATIES'.
'showing' is the link.
(Other definitions for treaties that I've seen before include "Treatise on international agreements" , "Rome and Versailles, for example" , "Written agreements between states" , "Treatise about pacts" , "Accords" .)