Dataset description vocabularies focus on provenance, ver-sioning, licensing, and similar metadata. VoID is a notable exception, providing some expressivity for describing subsets and their contents and can, to some extent, be used for discovering relevant resources and for optimizing querying. In this paper we describe the Sevod vocabulary, an extension of VoID that provides the expressivity needed in order to support the query planning methods typically used in federated querying. We also present a tool for automatically scraping such metadata from RDF dumps and give statistics about the size of the descriptions for the FedBench datasets.