It is grossly impolite to waste it. Convey the information requested and ask for that which you require and then terminate the conversation in a polite manner. The phone in a business context is no place to get chummy, it is functional. This does not mean that amenities must be ignored, but amenities are not the object of the conversation. Remember the limitations of the instrument.
All visual communication is lost.
Careful listening, together with direct speech, confined to the topic being discussed, can make up for this limitation. Most people do not communicate for a living, or, at least, they think they don't. The truth is that all of us communicate for a living, and enhancing the efficiency with which we can communicate will enhance the living we earn. The first step in selling a prospective resident on a rental unit is communication. The limitations of the instrument having eliminated a major factor in communication, the visual, the mode of carrying on the conversation must compensate.