As the science of building agents and agent based applications improves, agents are gradually making the transition from research laboratory prototypes to industrial applications. In an industrial setting pragmatic engineering issues related to the development and maintenance of agents come to the fore. In this paper a list of important engineering characteristics of agent architectures is presented. The list has the dual aims of providing evaluation criteria for agent users and design issues for agent architecture designers. Evaluation of an architecture with respect to the presented characteristics will allow industrial project managers to better assess the trade offs between architectures. Designing architectures that better fulfill the characteristics should lead to more industrially relevant architectures and successful agent applications. This list is designed to start discussion and raise awareness of industrial issues. It is hoped that over time good metrics and an evaluation methodology evolve which provide a robust framework for evaluating agent architectures with respect to industrial concerns.