Small cutters one may find extremely useful (4,8)
I believe the answer is:
nail scissors
'one may find extremely useful' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.
'small cutters' is the wordplay.
'small' becomes 'nail' (I am not sure about this - if you are sure you should believe this answer much more).
'cutters' becomes 'scissors' (I've seen this before).
'nail'+'scissors'='NAIL-SCISSORS'
Can you help me to learn more?
(Other definitions for nail scissors that I've seen before include "Manicurist's tool" , "using these on feet?" .)