The detector description is an essential component that is used to analyze data resulting from particle collisions in high energy physics experiments. We will present a generic detector description toolkit and describe the guiding requirements and the architectural design for such a toolkit, as well as the main implementation choices. The design is strongly driven by easy of use; developers of detector descriptions and applications using them should provide minimal information and minimal specific code to achieve the desired result. The toolkit will be built reusing already existing components from the ROOT geometry package and provides missing functional elements and interfaces to offer a complete and coherent detector description solution. A natural integration to Geant4, the detector simulation program used in high energy physics, is provided.