A query letter introduces your book to an agent: a one-line pitch, a short blurb of the kind that would go on a back cover, your genre and word count, sometimes comparable titles, and a brief note on who you are.
Unusually for submission advice, that formula is not invented. Named agencies publish it themselves. What is invented is nearly every rule about how to execute it.
Agencies Publish the Structure
Blake Friedmann give the fullest paragraph-by-paragraph breakdown found anywhere, asking for:
"An opening paragraph about your book, introduce it with the title, which genre you think it falls into, and a couple of comparative titles"
"A one-paragraph blurb for your book, such as you might find on the back of a book jacket; these are usually intriguing & compelling."
"A note on any significant previous publications or writing experience, if valid (don't worry if not!)"
"A note on any personal experience relating directly to the subject of the book, if you think it relevant"
Darley Anderson ask for "a one-line elevator pitch, a short blurb, the target market and genre of your work, and a short author biography including any competitions or prizes you have won for writing."
LBA want "a one-line pitch, a compelling blurb, some comparison titles or authors, and a little about yourself".
Writers House ask for a "query letter including your credentials, an explanation of what makes your book unique, and a synopsis".
The Bent Agency reduce it to a sentence: "Tell them briefly who you are and what your book is about."
Four agencies independently describing the same shape is about as well-sourced as submission advice gets. The elements they actually name are: a one-line pitch, a blurb, genre, target market and word count, comp titles, and a short bio.
Length: Only Two Agencies State One
A.M. Heath is the only agency found with a hard word limit: "maximum 500 words".
Janklow & Nesbit UK say a covering letter should "ideally be no longer than a page".
That is the entire sourced guidance on length. Every more precise figure you have read, the 250 words, the 350 words, the "three paragraphs and no more", appears in no agency's stated requirements. Aim for under a page and you satisfy both agencies that specify anything.
What Is Not Sourced
Worth knowing, because these rules are stated online with enormous confidence:
A rigid order. Blake Friedmann's four-part structure is theirs, not an industry standard. No other agency prescribes a sequence.
"Never open with a rhetorical question." Not stated by any agency checked.
"Never mention that this is your first novel." Contradicted, gently, by Blake Friedmann, who ask about previous publication and add "don't worry if not!"
A required word-count-and-genre line in a fixed position. Genre and target market are requested; where they go is not specified.
Comps as mandatory. Only about a third of agencies ask for them. See what are comp titles.
Follow the conventions if you like them, since they are harmless. Just do not believe that breaking one is a rejection.
Writing the Two Hard Parts
The one-line pitch. Graham Maw Christie ask for "a one to two line elevator pitch". The job is to convey the premise and the hook in a breath. What usually goes wrong is describing the theme rather than the situation: "a novel about grief and memory" tells an agent nothing, while "a widow discovers her husband kept a second family two streets away" tells them the book.
The blurb. Blake Friedmann's framing is the most useful instruction available: write it "such as you might find on the back of a book jacket", and note their word for what those achieve, "intriguing & compelling". A back-cover blurb sets up the situation and stops. It does not summarise the plot, and it certainly does not reveal the ending, which is the synopsis's job and the clearest structural difference between the two documents.
If you find yourself explaining the ending in the query, you have written a synopsis. If you find yourself withholding the ending in the synopsis, you have written a query.
Two Practical Points
Check whether the letter goes in the email body. Most agencies expect it there. Several US agencies delete emails with attachments unopened, which is covered in what goes in a submission package.
Check for an AI clause. These are recent and now widespread. HG Literary state: "We do not accept any query materials that were in any part AI generated." Note the scope: query materials, not just the manuscript. A.M. Heath require that submissions are "the original work of the author and not generated or co-written using artificial intelligence." If you are querying an agency with such a clause, the letter itself is covered by it.
What Deckle Does
A query letter is not manuscript content, so nothing in Deckle writes one. Two things help.
The word count in Compile gives you the figure agencies ask for, and it is the manuscript count rather than a file count, so it is the number to quote.
Keep the letter out of the Draft folder. Anything in Draft exports with the book. A query letter, synopsis and comp notes belong in Research, or in a document excluded from compile, so they never appear in an exported manuscript. That is a real failure mode: a submission DOCX with the query letter as its first page.
For the document you send alongside it, see what is standard manuscript format.
Common Mistakes
- Following a rigid template as though it were required. Only one agency publishes a structure, and it is theirs.
- Writing a synopsis instead of a blurb. The query withholds the ending; the synopsis reveals it.
- Pitching the theme rather than the situation. Themes do not distinguish books; premises do.
- Attaching the letter. Most want it in the email body, and some bin attachments unread.
- Exceeding a page. The two agencies that specify say 500 words and one page.
- Using AI to draft it where a clause forbids it. Several clauses cover query materials, not just the manuscript.
FAQ
Q: How long should a query letter be? A: Under a page. A.M. Heath cap it at 500 words; Janklow & Nesbit say no longer than a page. No agency states less.
Q: Is the standard query formula real? A: Yes. Four named agencies publish substantially the same structure.
Q: Should I include comp titles? A: About a third of agencies ask. Including them where unrequested is harmless.
Q: Do I say it is my debut? A: You can. Blake Friedmann ask about previous publication and explicitly say not to worry if there is none.
Q: Query letter or covering letter? A: The same document. UK agencies tend to say covering letter, US agencies query.