Once upon a time, a long time ago, I had clothes to wash. I was in Brussels, and the place I was staying had no washing machine, so I headed off for the nearest launderette.
What’s stuck in my mind all these years later is the instructions on the washing machine. On one side of the door they were in French, on the other, Flemish.
The French instructions took up 4 times the space, and talked about “making coins to be introduced into” the machine.
The Flemish on the other hand was blunt - “stick your penny in the slot”.
The point of this story? If you are struggling to explain what your promise is, try blunt.