Agent on vacation was resting around Crimean resort (5)
I believe the answer is:
yalta
'crimean resort' is the definition.
(I've seen this before)
'agent on vacation was resting around' is the wordplay.
'on vacation' suggests removing the centre (after the inside letters have vacated the word).
'was resting' becomes 'lay' (to lie down is to rest).
'around' says the letters should be written backwards.
'agent' with its middle removed is 'at'.
'at'+'lay'='atlay'
'atlay' in reverse letter order is 'YALTA'.
(Other definitions for yalta that I've seen before include "City on the Black Sea, where Roosevelt, Stalin and Churchill met in 1945" , "Ukrainian resort" , "Crimean resort and seaport" , "wartime meeting-place" , "Crimean resort city" .)