Informs — not about taking some measures (5,2)
I believe the answer is:
tells on
'informs' is the definition.
(telling on is a kind of informing)
'not about taking some measures' is the wordplay.
'about' is a reversal indicator.
'taking' indicates putting letters inside.
'some measures' becomes 'ells' (I've seen this before).
'not' reversed gives 'ton'.
'ton' going around 'ells' is 'TELLS ON'.
(Other definitions for tells on that I've seen before include "shops" , "Reports bad behaviour" .)