The company I work at emphasizes the up front contract in both internal and external communications.
“Hi, I need X minutes of your time to discuss Y. I intend for us to reach a decision/decide the next step next step/get your approval by the end of the call. Are you available at this date & time? Thanks!”
This was a generic version to get the point across, subject to a lot of factors. The meeting timing aspect is for the external facing comms.