Section173 Agreements and what council can do?

Hi All,
I have a question around a 173 agreement which I am about to have put on my title prior to having my land subdivided:

My subdivision is a battleaxe with an approved development plan for a dwelling at the rear with the existing home remaining. The 173 stipulates that the dwelling most be constructed as per the planning permit and that all parking spaces and landscaping must be in place. It is my understanding that after that I can request council remove the 173 agreement.

Where I am confused though is I will have sold my front property by the time I finish constructing the dwelling at the rear so I basically lose control over what the new purchaser decided to do?
So for example say I complete the landscaping as per the approved landscaping plan and then I sell it and the new buyer decides they want to rip it all up?

Secondly at what point if ever do council actually enforce the 173 agreement? Obviously If I ask to have it removed they may come and view the site but what about If you never ask to remove it? Can they randomly come over one day and say "hey you need to re-do all your landscaping". It doesnt make much sense!