3. Commands. Why do writers want to try to make an agent do more work than necessary? They send a one paragraph query and then say "go check out my website" or mail in a paper query with no SASE and say "email me your response." Why? Don't they realize the default answer on a query is "no" - the idea of query is that it should pitch the idea and do everything in its power to make the agent pause and say - oh wait, that might be interesting.
2. Have you ever... Rhetorical questions remind me of when I was teaching and I said repeatedly: "Don't use rhetorical questions to start off your essay. Seriously. Don't. Most of the time, they said ridiculously cheesy. The rest of the time, they just sound bad." It's also true for queries. (Same thing goes for Imagine... Don't start out that way either unless you're trying to make me think of the John Lennon song.)
1. Agent Search Engines that submit queries. Unpersonalized queries are plain unprofessional - If they start out "Dear Agent" or "Dear Literary Executive" or worse "To Whom it May Concern" I'm already annoyed they didn't take the time or effort to research what agent would be interested in their ideas. (Sure it's not me, but it makes my job easier, thinking "okay would [Agent] like this?" But even worse are the search engines! They send the emails out to 3475934857 agents at a time. It's like spamming - well it is spamming. And most of the time, the search engine sites have the wrong information - for instance, my agency does not rep poetry - no poetry, yet I always get at least one query a week for some sort of poetry or novella. And don't even get me started on the screenplays. Sell-A-Script drives me crazy.
And all this of course leads me to the number one thing that drives me crazy about queries no matter the day:
Blatantly Avoiding Directions. And really, all of the above can be factored into this one idea. There are websites and forums and blogs out there that tell a writer how to write a good query. They're not perfect and it'll take time for a writer to sift through all the information, but it's possible. And really, if a writer has taken the time, blood, sweat, and tears to write a novel, they can afford to take the time to follow an agent's directions.