The Model-Driven Architecture (MDA) technology toolset includes a language for describing the structure of meta-data, the MOF, and a language for describing consistency properties that data must exhibit, the OCL. Off-the-shelf tools can generate meta-data repositories and perform consistency checking over the data they contain. In this paper we describe how these tools can be used to implement runtime requirements monitoring of systems by modelling the required behaviour of the system, implementing a meta-data repository to collect system data, and consistency checking the repository to discover violations. We evaluate the approach by implementing a contract checker for the SLAng service-level agreement language, a language defined using a MOF metamodel, and integrating the checker into an Enterprise JavaBeans application. We discuss scalability issues resulting from immaturities in the applied technologies, leading to recommendations for their future development.