Traditional IDLs were defined for describing the services that objects offer, but not those services they require from other objects, nor the partial ordering in which they expect their methods to be used. In this paper we propose an extension of the CORBA IDL that uses a sugared subset of the polyadic p-calculus for describing object service protocols, aimed towards the automated checking of protocol interoperability between CORBA objects in open component-based environments. In addition, some advantages and disadvantages of our proposal are discussed, as well as some of the practical limitations encountered when trying to implement and use this sort of IDL extensions in open systems.