In our past research we have already defined a full service approach to compose MaaS services for multimedia data retrieving. This approach is based on a four phases process: description; filtering; clustering; and restitution. In this work, we are especially interested in the description and filtering phases of this process. Our contribution is two-fold. First, we propose to extend for the MaaS description the W3C recommendation on semantics for web services (SAWSDL). To do so, we use two types of ontologies: a Domain Ontology encompassing concepts that define semantics of the related business domain and a Multimedia Ontology encompassing concepts that define a set of annotation properties of the multimedia content. Second, we show how this extension allows addressing the problem of matching between MaaS services and user needs.