Goldilocks

     This weekend brought a lot of query revisions, and it got me thinking about a classic fairy tail. I know that a lot of getting an agent to jump at a query is a measure of being "just right", which is more a question of knowing it when you see it, but what about on the writing side of queries? As the writer, it's up to me to try and figure out that fit from my end. I got a lot of questions from various forum people regarding my query, usually questions asking for more and more detail, yet that seems to fly in the face of what queries are supposed to be. This leaves me with several questions.
     How much detail is necessary? How much is the right amount to know, and how much is too much? An even better question, though is the detail being asked for still necessary if the answer is uninteresting? Is it better to have that bit of mystery in a query, that unanswered question, than to give the answer that falls flat? Lastly, at what level do I write at for an agent. It's my understanding that agents representing certain works are more or less experts in their genres. Should I expect them to get certain conventions of the genre? If I spell out every last thing am I insulting their intelligence? Do I ignore what many other writers (most not in my genre) have said about my query and go with my gut?