in most working and proposed multiagent systems, the problems of identifying and locating agents that can provide specific services are of major concern. A broker or matchmaker service is often proposed as a solution. These systems use keywords drawn from application domain ontologies to specify agent services, usually framed within some sort of knowledge representation language. However, we believe that keywords and ontologies cannot be defined and interpreted precisely enough to make brokering or matchmaking among agents sufficiently robust in a truly distributed, heterogeneous, multiagent computing environment. This creates matching conflicts between, a client agent’s requested functionality and a service agent’s actual functionality. We propose a new form of interagent communication, called functional validation, specifically designed solve such matching conflicts. In this paper we introduce the functional validation concept, analyze the possible situations that can arise in validation problems and formalize the mathematical framework around which further work can be done.