Slaver not using right tool (6)
I believe the answer is:
dibble
'tool' is the definition.
(dibble is a kind of tool)
'slaver not using right' is the wordplay.
'slaver' becomes 'dribble' (synonyms).
'not using' is a deletion indicator.
'right' becomes 'r' (common abbreviation).
'dribble' with 'r' taken out is 'DIBBLE'.
(Other definitions for dibble that I've seen before include "Small pointed tool to make holes in earth" , "Small pointed tool to make holes for bulbs" .)