A Grimoire is a magician's manual for invoking demons (Oxford English Dictionary). Likewise, the Grimoires registry hosts descriptions of services and workflows, which a scientist can use for forming their complex scientific experiments. However, service and workflow interfaces are sometimes underspecified and therefore difficult to use in an automated manner; hence, the myGrid registry augments their interfaces with metadata such as functionality, semantic information about their inputs and outputs, or various metrics (e.g. perceived quality of service, trust).