Should a RESTful API have a schema?
<p>I was told recently that a proper RESTful API should define a schema for the resources representations it accepts and returns. For example XSD for XML and JSON Schema for JSON. </p>

<p>However in all the books and articles on REST I went through this has never seem not only prominent, but even mentioned.</p>

<p>Could someone provide some authoritative resources, to clarify if we should be providing schema when developing RESTful APIs?</p>