Tool's fixed, we're told (5)
I believe the answer is:
spade
'tool's' is the definition.
(spade is a kind of tool)
'fixed we're told' is the wordplay.
'fixed' becomes 'spayed' (fix can mean to spay an animal).
'we're told' indicates a 'sounds like' (homophone) clue.
'spayed' sounds like 'SPADE'.
(Other definitions for spade that I've seen before include "Fictional detective" , "a gardener's needs?" , "Small shovel" , "black suit" , "One in a suit" .)