An ontology is an explicit formal conceptualization of some domain of interest. Ontology application is widely used in multi-agent systems. Ontology provides the channel through which software agents interact; therefore, if the ontology definitions have not been sufficiently evaluated, communication between software agents may not succeed. Ontology evaluation guarantees to end users the correctness and completeness of ontology definitions and software. The goal is to detect wrong, incomplete or missed definitions in the ontology. The study is based on multi-agent system application for raw materials management task. The common ontology is used for agent cooperation; the quality of ontology is measured with ontology evaluation techniques.