In this paper we demonstrate how diagrams constructed using general-purpose drawing tools in the context of agile language development processes can be annotated and consumed by model management programs (such as simulators, model-to-model and model-to-text transformations). The aim of this work is to enable engineers to engage in programmatic model management early in the language development process, so that they can explore whether or not the languages and models constructed are fit for purpose. We demonstrate a proof-of-concept prototype developed atop the Epsilon platform and a flexible graph definition language (GraphML).