On my sojourn in Fortaleza, I spent some time thinking about the problem of capability modelling. The following is the abstract of a preliminary paper on this, which describes an implemented, simple system.One of the persistent problems in managing the interaction between distributed collections of knowledge based systems is to be able to coordinate the communication between systems without having continually to ask each system for information about what it can do. The idea of capability descriptions is that each KBS can advertise the main things which it can do and these advertisments may be used to plan coordination between KBSs to achieve given goals. Often coordination is through a broker system which reads the advertisments and makes plans on behalf of its clients. We describe a simple but powerful way of implementing this sort of broker.