Tools breaking laws (4)
I believe the answer is:
awls
'tools' is the definition.
(awl is a kind of tool)
'breaking laws' is the wordplay.
'breaking' indicates anagramming the letters.
'laws' is an anagram of 'AWLS'.
(Other definitions for awls that I've seen before include "Pointed hand-tools" , "Small piercing tools" , "Laws about boring tools (4)" , "Tools for punching small holes" .)