Designing agent interactions with Pericles Andrea Passadore, Christian Vecchiola, Alberto Grosso, and Antonio Boccalatte l.i.d.o. - DIST, University of Genoa, Via Opera Pia 13, 16145 Genoa, Italy {passa,christian,agrosso,nino}@dist.unige.it http://www.lido.dist.unige.it Abstract. In this paper we present the Pericles Suite for the develop- ment of ontologies and interaction protocols in AgentService, a frame- work for multi-agent systems. The Pericles main goal is to increase agent communication capabilities, allowing agents to compose messages by us- ing semantic rules and to manage dialogs with peers by following an interaction structure. We describe the whole lifecycle of ontologies and interaction protocols, showing how the former are involved in the latter. Key words: Ontology, multi-agent system, interaction protocol, AUML, code generation, C#. 1 Introduction Since the first definition in 1977, given by Hewitt [1], where an agent (called actor) is a self-contained, interactive and concurrently-executing object, possess- ing internal state and communication capability, software agents have always exposed the ability to talk with their peers. This ability allows agents to coor- dinate their tasks with collaborative peers, to share information, and to access the services offered by other agents. An agent must know the syntax and the semantic of messages to speak with its interlocutor. Usually, syntactical and se- mantic rules are encoded within the agent application space; if these rules are external and shared by agents, they are named ontology. Usually an ontology is a hierarchical data model describing all the relevant entities of a discourse do- main, defining their relationships, rules, and constraints. Therefore, an ontology within a Multi-Agent System (MAS) contains a clear representation of message contents, which agents must follow to be understood. The ontology service pro- vides a strict formalism to represent syntax and semantics of message content; it also represents knowledge bases, upon which agents found their activities and speculations. In order to ease interactions among agents, we introduce the ontology and interaction protocol services in the AgentService framework [2], using well-known software (Prot´ eg´ e and Microsoft Visio) and developing new tools, grouped in the Pericles Suite. As Pericles was an able orator of the Ancient Greece, the Pericles Suite helps the AgentService agents to talk efficiently, sure to be understood