Conceiving a mobile collaborative system involves determining, at an early stage of the development process, the interaction and awareness services that such an application will provide to end-users, software agents, and smart objects. The literature recognizes this definition as a challenging activity that requires the joint participation of stakeholders and developers in order to get an agreement about these services. This paper presents a collaborative visual modeling tool intended to help both parties to create, evaluate and evolve models that represent this service agreement through several views. The tool was evaluated and the results of this assessment study and the feedback issued by the participating researchers and developers offer us positive indications in its practical application.