REST Services documentation for end client After creating a REST services using Services module there is always somebody who develops a client for you endpoint. And this developer must know which services we have, which parameters to pass, which method to use etc.

Is there any automatically generated documentation for Services that are created? 
(E.g. something like to WSDL document for SOAP.)
There is indeed:

Services Documentation API


  The Services Documentation module generates API documentation for your site’s Services resources. Most of the documentation is generated automatically, using the resource information contained provided by Services. However, this module provides you with the ability to easily extend that documentation.