Vacuous politician going through the escort agency's terms (5)
I believe the answer is:
empty
'vacuous' is the definition.
(I know that vacuous can be written as empty)
'politician going through the escort agency's terms' is the wordplay.
'politician' becomes 'MP' (Member of Parliament).
'going through' is an insertion indicator.
'terms' says to take the final letters (term can mean the end of something).
The last letters of 'the escort agency' are 'ety'.
'mp' going within 'ety' is 'EMPTY'.
(Other definitions for empty that I've seen before include "Unoccupied" , "Vacant - futile - blank" , "(Of words) lacking sincerity" , "Containing nothing" , "Cleared out" .)