Collaborative systems (SiCos) support or enable human interaction online; this involves users communicating not only with the system, but also, and mainly, with each other. Theoretical contributions reveal and empirical studies illustrate and provide evidence of the influence of SiCos on the communication among users (USU communication), the users´ experience, and ultimately on the social activity supported by the system, as well as group dynamics. The effects of SiCos, especially the social effects, call for the development of design tools that help designers make more informed decisions. In this work, we introduce Manas, a Semiotic Engineering epistemic tool that enables designers to represent their USU communication project, and offers them qualitative feedback on the potential social effects of their project on interaction between users and the system as well as among themselves. In doing so, Manas leads designers to reflect upon both the problem being handled and the proposed solution, allowing them to make more conscious decisions. Furthermore, Manas registers the underlying rationale in the USU communication project, which is a valuable source of information and study of the design process and its product, and creates favorable conditions for the transmission of this knowledge to users through the system interface. Users will then be able to use the system more efficiently. Thus Manas potentially enhances the quality of SiCos.