“We will send you the details” is where an interested family quietly becomes a lost one.
A call that has gone well should finish with something that exists in a calendar: a visit on Saturday at eleven, a counselling slot on Tuesday, a demo lecture on Thursday evening, a document list and the date it is needed by. Offering two specific times works better than offering to find a time, because the second asks the family to do the work.
A call that has gone badly should also finish cleanly. A family that has already taken admission elsewhere deserves a short, warm exit — they have a younger child, a cousin, and neighbours who are still deciding.