I have written a humorous novel but as this genre is a very wide term I have queried with "comedic misadventure". I have also called it "character driven situation comedy". The novel is in the vein of P.G. Wodehouse - ie. the plot thickens as the stakes become higher. What would be the best description for my query letter in regard to "Agent jargon".
Regardless of what genre/label you give yourself, ease up on the 'quotation marks'. They're akin to Capital Letters on Proper Nouns - that is, they make your query letter look like a real estate agent's ad for a 'Renovator's Delight'.
A lot of writers, when querying, tie themselves in knots over the genre of their book. Here are three labels I like: fiction; non-fiction; children's. Beyond saying it's one of those, you don't have to give it a label or genre if you don't want to know. Genres are for booksellers, so they can shelve the book more easily. I apply a genre/label to a manuscript when I send it to a publisher so that they know what they would call it when they sell it in to booksellers. Sometimes they'll change the genre; sometimes the bookseller will. So there's not a lot of point in you worrying about it at this stage. Tell me if it's fiction or not, then give me a short description of it. I'll be able to work it out from that.
I should add that genres are useful when you're querying US agents, because they specialise (a luxury we can't afford here on the large, mostly desert island). So it's good for you to identify that your novel is comic, so that you don't send it to an agent who only wants romance novels. But if you've got that part right, I can't imagine any agent is going to reject you just because you don't drill down to the most detailed level of labelling. A well-written letter and an accompanying well-written story are what's important when we're considering your submission.