The four facts a booking actually needs
The four facts are the address, the hour, the length and the figure, and a message that carries all four is usually answered in a single reply.
People overthink the first message. It needs four things and it does not need anything else. Where you are, with a floor and a room or apartment number. When you want her. How long the session runs. And the figure that goes with that length, which you can read off a profile before you write.
The fifth thing, which is optional
A name from the roster, if you have already looked and found somebody. That is welcome and it speeds things up. If you have no name in mind, say so plainly and ask who is free at that hour, and the reply will tell you who is. Asking both questions at once, the hour and the name, is what turns a booking into a five message negotiation.
What is not one of the four
Anything about what the session itself contains. That belongs to the woman who knocks and she will set it out herself, which is why a thread never answers it and never hints at an answer. A message that spends its length there gets a reply that quietly answers the four facts instead, and the guest usually works out why within a message or two.
A worked example
Two hours, tonight at nine, a hotel room in the centre with the floor and the room number written out, 360 euros, and a name you found on the roster. That message gets an answer in one reply: free or not free, the arrival window, and the sum that goes ahead if this is your first booking. Nothing else is needed to make an evening happen. The booking page shows the same thing laid out step by step.