Truth lies between Tim Berners-Lee and Noah Mendelsohn . RDF can describe documents with nouns and verbs. Noah is asking whether it can describe adverbs. WSDL describes the service itself. In this discussion, an implicit assumption appears to be that RDF will be used to specify semantic web.
Semantic web expresses information about web services.
Semantic web models will accumulate more information as time progresses. Semantic web can be thought of as database schemas. It is likely that an extension of current UML and RDF will be needed for metadata and modeling.