Composability is the capability to select and assemble re-usable simulation components in various combinations into simulation systems to meet user requirements. The De-fense Modeling and Simulation Office’s Composable Mis-sion Space Environments program, seeks to develop con-cepts, technologies, and processes to enable the rapid, efficient, and flexible assembly of simulation systems from components. A workshop was held to examine the current state of composability, refine its definitions and intentions, identify capabilities and technologies needed to support practical composability, and propose research objectives and programmatic initiatives to move towards the goals of the Composable Mission Space Environments (CMSE) program. Approximately 35 experts from government, in-dustry, and academia participated in four working groups (WGs). This paper reports the findings and recommenda-tions of the Data and Metadata WG. The WG identified the crucial functions served by metadata descriptions of components in composable development, specified attrib-utes of the components to be represented in the metadata, and sketched a high level concept of operations describing the roles and relationships of metadata stakeholders. This paper also reports the recommendations of all of the WGs for future actions in support of composability.