Abstract. In open agent societies, communication protocols and strategies cannot be assumed to always match perfectly, because they are typically specified by different designers. These potential discrepancies raise a number of interesting issues, most notably the problem of checking that the behaviour of an agent is (or will be) conformant to the rules described by a protocol. In this paper, we argue that the ability to merely conform to a protocol is not sufficient for an agent to be a competent user of that protocol. We approach the intuitive idea of protocol competence by introducing a notion that considers, broadly speaking, an agent’s ability to reach a particular state of the interaction and we provide preliminary results that allow us to automatically check competence in the context of a specific class of logic-based agents. Finally, we illustrate how these results can facilitate the customisation of protocols used by agents that are not fully competent.