You have to try and see it from their viewpoint. The guys get dozens of messages a day and try to set up their schedule in between seeing clients. They are not secretaries and if anything are really bad at secretarial skills. And you'd be amazed at how many people intentionally try to waste time and never book. They're just after free online contact with a hot guy and it becomes a tedious game of spotting them.
A "normal" routine would be a guy finishes a 5pm incall at 5:20 and has to groom for a 6:30pm incall and hops on the phone for messages to arrange future dates and tries to get to as many of the 20 messages as possible but one or two of the first 10 want to get into detail about some fetish or see pics or talk about sex for as long as they can keep you online. You have to be rude to discourage them from wasting your time again and this rudeness may carry over into other texts with unknown clients. It's their livi hood and they have to be efficient as possible. 90% of what they want to know is what time do you want a slot and incall or outcall. The rest is details and there may be a dealbreaker. The ones they appreciate are those who say " I'd like an outcall at 7pm today at xxxx address." I'm a top (or bottom). Who pays the Uber, smoking or not, kissing, etc are all details they work out (or very rarely don't).
They're not looking for online romance or pen pals.And they have a lot of other texts to try and answer and that's why they may seem curt.