This paper seeks to move towards an un-encoded metadata standard supporting the description of environmental numerical models and their interfaces with other such models. Building on formal metadata standards and supported by the local standards applied by modelling frameworks, the desire is to produce a solution, which is as simple as possible yet meets the requirements to support model coupling processes. The purpose of this metadata is to allow environmental numerical models, with a first application for a hydro-meteorological model chain, to be discovered and then an initial evaluation made of their suitability for use, in particular for integrated model compositions. The method applied is to begin with the ISO19115 standard and add extensions suitable for environmental numerical models in general. Further extensions are considered pertaining to model interface parameters (or phenomena) together with spatial and temporal characteristics supported by feature types from climate science modelling language. Successful validation of parameters depends heavily on the existence of controlled vocabularies. The metadata structure formulated has been designed to strike the right balance between simplicity and supporting the purposes drawn out by interfacing the Real-time Interactive Basin Simulator hydrological model to meteorological and hydraulic models and, as such, successfully provides an initial level of information to the user.