In an open component market place, interface description languages (IDLs) such as CORBA's provide for the consumer only a weak guarantee (concerning type signatures) that a software service will work in a particular context as anticipated. Stronger guarantees, regarding the intended semantics of the service, would help, especially if formalized in a language that allowed static checking of compatibility between the server and the client's service descriptions.We propose an approach based on a family of formalisms called description logics (DLs), providing three examples of the use of DLs to augment IDL: (1) for the CORBA Cos Relationship service; (2) for capturing information models described using STEP Express, the ISO standard language used in the manufacturing domain (and a basis of the OMG PDM effort); and (3) constraints involving methods.DLs, while being less powerful, do offer certain advantages over traditional formal specification techniques. First, they typically support decidable (sometimes even efficient) reasoning algorithms. Second, DLs excel at modeling natural domains, and are thus well-suited for specifying applicationand domain-specific services.