Make another promise to agent on clifftop (8)

'make another promise' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'agent on clifftop' is the wordplay.
'agent' becomes 'rep' (short for representative).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'clifftop' becomes 'ledge' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'rep'+'ledge'='REPLEDGE'

'to' acts as a link.

Can you help me to learn more?