Page "Literary agent" Paragraph 2

Literary agencies can range in size from a single agent who represents perhaps a dozen authors, to a substantial firm with senior partners, sub-agents, specialists in areas like foreign rights or licensed merchandise tie-ins, and clients numbering in the hundreds.

Most agencies, especially the smaller ones, will specialize to some degree, representing authors who ( for example ) write science fiction, or mainstream thrillers and mysteries, or children's books, or highly topical nonfiction.

Very few agents will represent short stories or poetry.