The last sort of quality needed by cat burglars (7)
I believe the answer is:
stealth
'quality needed by cat burglars' is the definition.
(I've seen this before)
'the last sort' is the wordplay.
'sort' is an anagram indicator.
'the'+'last'='thelast'
'thelast' with letters rearranged gives 'STEALTH'.
'of' acts as a link.
(Other definitions for stealth that I've seen before include "Halt set in furtive manner" , "quality needed by cat burglars" , "The last (anag.)" , "By which taxes go up" , "Avoiding detection by moving carefully" .)