Examine empty trolley that's barely sufficient (6)
I believe the answer is:
scanty
'barely sufficient' is the definition.
(I've seen this in another clue)
'examine empty trolley' is the wordplay.
'examine' becomes 'scan' (scanning is a kind of examining).
'empty' says to hollow out the word (remove centre letters).
'trolley' with its middle removed is 'ty'.
'scan'+'ty'='SCANTY'
'that's' is the link.
(Other definitions for scanty that I've seen before include "Lacking in amplitude or quantity" , "Of small extent; barely sufficient" , "(Of clothing) revealing" , "Give (to a good cause)" , "Spare" .)