Agitator beginning to tire Russian coin producer? (12)
I believe the answer is:
troublemaker
'agitator' is the definition.
(thesaurus)
'beginning to tire russian coin producer?' is the wordplay.
'beginning to' indicates taking the first letters.
'russian coin' becomes 'rouble' (I've seen this before).
'producer?' becomes 'maker' (producer is a kind of maker).
The first letter of 'tire' is 't'.
't'+'rouble'+'maker'='TROUBLEMAKER'
(Other definitions for troublemaker that I've seen before include "source of agitation" , "Ringleader" , "Stirrer" , "Incendiary" , "Agitator" .)