Being in the agent game is hard work, no? The query letter takes a million drafts, the query specific query letter takes even more. But there are reasons why this is done:
1) You know how you say, "My novel is complete at x-amount of words"?
2) You know how you say, "This is the genre of my novel"?
3) You know how you say, "This is a simultaneous submission"?
4) You know how you wrote a million drafts and edited the heck out of your novel?
We do these things, we write these things, so when an agent says, "Please send me fifty pages," or "Please send me your entire manuscript," you can push, "Upload Document" without flinching, or without having to go through and edit your 200+ page novel.
You make sure your word count is in the query, so the agent knows what they're getting into. You know your genre so your agent can start figuring out how to best market your novel. You drop the "simultaneous submission" to let the agent know that you're not putting all your eggs in one basket.
Even if your request gets rejected, keep your head up, allow yourself the 15 minute window, and start sending queries again.
Happy submitting! :)