Informed by a couple of students taking everything into account (3,4)
I believe the answer is:
all told
'taking everything into account' is the definition.
(I've seen this before)
'informed by a couple of students' is the wordplay.
'informed' becomes 'told' (telling is a kind of informing).
'by' is a charade indicator (letters next to each other).
'a couple of students' becomes 'all' (I am not sure about this - if you are sure you should believe this answer much more).
'told' after 'all' is 'ALL TOLD'.
Can you help me to learn more?
(Other definitions for all told that I've seen before include "sum" , "Including everything" , "In summary" , "Altogether" , "With everything or everyone taken into account" .)