Few arts are spoilt by this tool (7)
I believe the answer is:
fretsaw
'this tool' is the definition.
(I've seen this before)
'few arts are spoilt' is the wordplay.
'are spoilt' indicates an anagram.
'few'+'arts'='fewarts'
'fewarts' with letters rearranged gives 'FRETSAW'.
'by' acts as a link.
(Other definitions for fretsaw that I've seen before include "Woodworking tool" , "Woodcutter" , "Tool for cutting designs in wood" , "cutter" , "Fine-toothed tool" .)