[steveklabnik]

The important part is that this is all documented in the media type. Of course, computers aren't able to just figure out what's up, that's why it's agreed upon beforehand.

> You can't truly add/remove new functionality

You can absolutely add new functionality, because rule #1 of clients that work this way is 'ignore things you don't understand.' Removal will obviously break things, so it's important to handle this in the appropriate way.

I guess ultimately my point is that these kinds of APIs are significantly different, and come with a very different set of constraints/goals/implementation details. It's like you're saying "well, I don't have a full list of function calls I can make!" because you're used to SOAP where there's a WSDL and 'RESTful' APIs don't have description documents. Of course! It's a different architecture!