I have found it useful to be out with my labels. It makes it clear to people not only that I'm not interested in relationships now, but that I probably never will be, and I've accepted that. Using something more general sometimes makes people think I'm just not ready yet or haven't found the right person yet. Several people have realized they were ace spectrum because I came out as asexual and explained what that meant to them and others. And for those who aren't, maybe they won't be as surprised when the next person they know comes out as asexual to them. That said, I don't come out to everyone, or even everyone who asks about my relationships. It is completely your decision whether or not to come out, and how many people to come out to if you decide to come out.