Entering into an agreement that’s potentially good (9)
I believe the answer is:
promising
'good' is the definition.
(thesaurus)
'entering into an agreement that's potentially' is the wordplay.
I cannot quite understand how this works, but
'into' could be 'in' and 'in' is found within the answer.
'an' could be 'i' (Roman numeral for one) and 'i' is present in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for promising that I've seen before include "Showing great potential" , "Giving one's word" , "Favourable -- hopeful" , "Encouraging" .)