Tool, visibly sore, covered in soap (8)
I believe the answer is:
lathered
'covered in soap' is the definition.
'tool visibly sore' is the wordplay.
'tool' becomes 'lathe'.
'visibly sore' becomes 'red'.
'lathe'+'red'='LATHERED'
(Other definitions for lathered that I've seen before include "flogged" , "Created a froth" , "Soaped as for shaving" .)