No agent coordinates the other agents to plan the global task. TAs are low level agents and represent both providers and users. They are introduced as needed, such as when a user connects for the first time. These TAs are managed by a MA according to its expertise. The broker's knowledge is represented by the network of beliefs of the various agents.
MAs are high level and sedentary.
They can contain numerous TAs, and are created when new sites are installed. MAs are responsible for controlling creations, suppressions, and the TAs which compose it. Their skills are those of their TAs and the beliefs they have in their TAs. MAs view things locally and has no direct beliefs in TAs from other MAs. They also gain beliefs in others MAs throughout their life.