The process of agent communication modeling has not yet received much attention in the knowledge systems area. Conventional knowledge systems are rather simple with respect to their communication structure: often it is a straightforward question-and-answer sequence between system and end user. However, this is different in recent intelligent multi-agent systems. Therefore, agent communication aspects are now in need of a much more advanced treatment in knowledge management, acquisition and modeling. In general, a much better integration between the respective achievements of multi-agent and knowledge-based systems modeling is an important research goal. In this paper, we describe how agent communications can be specified as an extension of well-known knowledge modeling techniques. The emphasis is on showing how a structured process of communication requirements analysis proceeds, based on existing results from agent communication languages. The guidelines proposed are illustrated by and based on a large-scale industrial multi-agent application for distributed energy load management in industries and households, called Homebots. Homebots enable cost savings in energy consumption by coordinating their actions through an auction mechanism.