Multi-Agent Systems (MAS) architectures are gaining popularity for building open, distributed, and evolving software required by systems such as information integration applications. Unfortunately, despite considerable work in software architecture during the last decade, few research efforts have aimed at truly defining patterns and languages for designing such multiagent architectures. We propose a modern approach based on organizational structures and architectural description languages to define and specify multi-agent architectures notably in the case of information integration system design as illustrated in this paper.