Meet my Hatchet of Death (or, some other colorful description RC Lewis and I come up with at any given moment). This is how I edit myself, it is how I edit others. If you think you want to play with me and my hatchet, shoot us an email.
We all know the first line of a query is your "hook." I call the last line the "sinker." You want it to punch them in the face, in a nice, friendly kind of way that makes them unable to forget you after having read the 300 other queries in their inbox.
If you're looking for query advice, but are slightly intimidated by my claws, blade, or just my rolling googly-eyes, check out the query critique boards over at AgentQueryConnect. This is where I got my start, with advice from people smarter than me. Don't be afraid to ask for help with the most critical first step of your writing journey - the query. My comments appear in green.
I’m seeking representation for my middle-grade novel, Miss Everything. Because of the fact that you wrote a query, the agent assumes you are seeking representation. Given your interest in contemporary, realistic fiction with an authentic voice, I thought it might prove a good fit for your list. This is a good way to personalize it - this little statement shows that you've done your research and are querying this agent for a specific reason, not just because they are an agent and you are a writer searching for an agent. The one thing I'll say is that I think this sentence / paragraph works better at the end of the query. It's a personal opinion, but I think starting with the hook is the best approach.
For twelve-year-old sculptor Amy Dow, seventh grade is one big torture-fest served up by the spectacularly evil Megan and Emily. Interesting. It's not a stellar hook, but an MG sculptor is something new. Humiliated and frozen out, she’s Miss Victim until the arrival of Sonia, the new girl. Seizing her chance to be popular – or at least not picked on – she feeds Sonia to the bullies and lets them smell the blood. Suddenly she’s Miss Popularity, and she’ll do anything to stay there, even if it means sacrificing her art, her family – and Sonia. I definitely need more details here - why would simply replacing the victim suddenly make Amy popular? And why would she have to sacrifice her art and her family to remain popular? It also sounds like she already sacrificed Sonia, so it's not much of a loss to state it again. When their bullying goes too far, Amy risks her newfound status in a supreme act of defiance. Yep, get the details in here. How does it go too far? What is her act of defiance? Shifting from victim to bully and back again, Amy discovers that she just can’t be Miss Everything. Now she must make a terrible choice – and she knows they’ll eat her alive either way. I don't understand what the choice is if she's already shifted, and shifted again. The sinker line here is good, but the overall vagueness isn't working in your favor. Get the details in there. Make it clear what distinguishes your MG from every other bullying book out there right now.
A graduate of the Humber School for Creative Writing and a member of the Professional Writers Association of Canada, my short fiction has appeared in Jelly Bucket, Stone Highway Review, Double Reed, the Four-Cornered Universe, the Toronto Star, the National Post, Marketing, Upbeat, Mind, Body & Spirit and the Beach-Riverdale Mirror. My credits also include Nigeria: the Land, People and Culture educational series. Great bio here, it definitely shows that you know your stuff.
Miss Everything is complete at 25,000 words. Per the instructions on your website, I’m attaching a synopsis and the first twenty-five pages of Miss Everything. You don't need to state that it's complete - the agent will assume it is since you are at querying stage. Again you've done a good job here of showing that you have done your research by stating that you are following the instructions on their site. I'd take the earlier sentence from your beginning para and stick it here to drive that "I've done my research" point home.