Brief inspection appears extremely effective (4-3)
I believe the answer is:
look-see
'brief inspection' is the definition.
(I've seen this before)
'appears extremely effective' is the wordplay.
'appears' becomes 'looks' ('look' can be a synonym of 'appear').
'extremely' says to hollow out the word (remove centre letters) (only the extremes of the word are used).
'effective' with its centre taken out is 'ee'.
'looks'+'ee'='LOOK-SEE'
(Other definitions for look-see that I've seen before include "Dekko" , "Brief inspection" , "Young's - relates stress and strain (Physics)" , "Survey, inspection" , "Inspection (colloq.)" .)