Re: For an agent
No, an outline is also for novels. More often than not, you need both a synopsis and an outline for selling a novel.
A synopsis is a short, 1-5 page, overview of the entire novel. An outline is much longer, is most often done chapter by chapter, and can be 100 pages in length, though most are shorter.
Being able to write a good outline for the novel is one of the most valuable selling tools a new writer can have.
A "standard" novel partial at the publishers and agents I've dealt with is pretty simple. When you open the package, you find a cover letter on top. Under this is a short synopsis. Under this is the first three chapters of the novel. Under this should be a detailed, chapter by chapter outline of every chapter after chapter three.
Some writers, Robert J. Sawyer comes first to mind, write outlines that are much like synopses, but they do write a synopsis and an outline for every novel. Sawyer does it in reverse of most writers I know, writing the outline before the novel is written, and the synopsis after the novel is written, but it still works.
But it is much easier for most writers to write a detailed outline after the novel is finished.
Outlines are NOT just for nonfiction works, and a new writer who doesn't know how to write and use an outline is at a serious disadvantage.
My own novel outlines were always roughly forty pages in length, which is probably above average, but still shorter than some writers I've known.
I've sold my last three novels based only on a one or two paragraph synopsis of the novel, but outlines for novels ar estill extremly valuable, and every new writer should know how to write one.
The query letter just isn't a very good tool for new writers. Neither is a synopsis without a good outline. It's much easier to get an agent if the agent can actually read your fiction, and a novel proposal, complete with both synopsis and a detailed outline, fits in a small package, and can save both the writer and the agent much valuable time.
The sunopsis, three chapter, plus detailed outline is also an excellent selling tool for editors, and I know several agents who prefer to submit to publishers using this package.