This document outlines plans for a new content type called a Data Descriptor to be launched in May 2014 by the journal Scientific Data. A Data Descriptor will consist of an article component and a structured metadata component. It aims to provide all the information needed to understand, reuse, and reproduce datasets in a peer-reviewed publication. This will help address barriers to data sharing by providing credit for sharing data and making datasets more discoverable and reusable through standardized metadata. The Data Descriptor is presented as a complement to traditional journal articles and data repositories.