My own client list includes nearly a dozen reporters and columnists. As a former magazine writer and editor, I pay special attention to queries from journalists and columnists, and I believe many other agents do, too. It’s always important to include your credentials in a query letter. Your reporting and column writing may even be what grabs an agent’s attention, but what most interests any agent will always be a high-quality book proposal or manuscript. And no matter how good they are, some reporters and columnists aren’t able to make the transition from short-form journalism to the long form of books.