Mata Hari, perhaps -- young woman smuggling good telescope (8)
I believe the answer is:
spyglass
'telescope' is the definition.
(spyglass is a kind of telescope)
'mata hari perhaps young woman smuggling good' is the wordplay.
'mata hari perhaps' becomes 'spy' (mata hari is a kind of spy).
'young woman' becomes 'lass' (lass is a kind of young woman).
'smuggling' indicates putting letters inside (I've seen this in other clues).
'good' becomes 'g' (abbreviation).
'spy'+'lass'='spylass'
'spylass' placed around 'g' is 'SPYGLASS'.
(Other definitions for spyglass that I've seen before include "little scope" , "that magnifies" , "he can see through it!" , "lookout's aid" , "viewer" .)