Order an Aga perhaps on the phone (7)
I believe the answer is:
arrange
'phone' is the definition.
The answer and definition can be both to do with communicating as well as being verbs in their base form.
Maybe they are linked in a way I don't understand?
'order an aga perhaps on' is the wordplay.
'order' becomes 'range' (synonyms).
'an aga perhaps' becomes 'ar' (I am not sure about this - if you are sure you should believe this answer much more).
'on' is a charade indicator (letters next to each other).
'range' after 'ar' is 'ARRANGE'.
'the' acts as a link.
(Other definitions for arrange that I've seen before include "Organise, plan" , "Put in neat order" , "Set in place" , "Plan, organize" , "Orchestrate - order" .)