< Do I need to write anything here? >
Yes, your body should contain content. A title alone is not the correct way to go. If your title contains the full content of your question then there are two possibilities:
- Your question is not all that good to begin with
- You put way too much information into your title
For example, what you could have asked is:
Title: Does a question always need a body?
Body: Sometimes I have a question which can be fully expressed in the title. If that is the case, should I just leave the body empty or do I need to restructure my question?
Now your title is short, sweet, but descriptive, while the body contains the full question you're asking.
In short, if your title says it all, you're doing it wrong. A title needs to be descriptive, but a title is not the question.
If your question can be explained in one sentence, then it fits one or more of the following categories:
- Lacks research effort
- Is unclear
- Is not useful
- Not a real question
- Too localized
Short: You're doing it wrong. If your question only consists of one sentence, there's a very straight out possibility that it is a very poor question.
Now I'm going to do something I've never done before, I'll hopefully never do again and which I've frowned upon very often: Did you try to enter your question (that one line) into a searchmachine?
There's nothing special about StackOverflow. The question of title-vs-body affects almost every piece of communication.
The title (and perhaps abstract or cover text) serves to allow a potential audience to decide whether or not they want to engage with you. Your audience is busy and has many better things to do, so the title should be honest and accurate enough to let them decide confidently whether opening the post is in their interest or not.
The body contains the entire, complete subject matter, without dependencies. People may have opened the post a long time ago when they went through their daily agenda and decided what to put on their plate for the day. They expect to be presented with a complete description of the problem and not have to play mental treasure hunts to discover how to best serve you.
In a nutshell: Write the title for everyone to see. Write the body for your interested audience who has already committed their attention to you.
If someone opens your post and is frustrated that it doesn't suit her, you're doing it wrong. If an eligible reader dismisses your post because the title doesn't delineate the domain properly, you're doing it wrong. If an expert on the subject doesn't understand what you've written in the body, you've done it wrong.
Think about the question title as the label to a jar of cookie, and the content of the question being the cookie inside.
The title of the question is important in drawing attention to your question - as how the external appearance will draw people attention to the jar of cookie.
But what's important is the content of the question (or the cookie in this case). Even if the jar is not beautifully decorated with a flash label, some people will still buy it, while no one will like an empty container that says there is cookie inside. Similarly, the body of your question should be able to survive on its own without the title.