Hi Manuel
You are right - the schema description is gone from the draft, I'll fix that. Thanks.
The most obvious choice is JSON Schema as you suggest yourself, but I won't restrict the format to that only. So JSON Schema is recommended but not required.
For "schemaUrl" the client can look at the returned content type to figure out the schema type.
For "schema" (embedded schema) the default is JSON schema unless something else is, somehow, identified. I recommend looking for "$schema": "
http://json-schema.org/draft-04/schema#" in the embedded schema definition (which obviously would have to be encoded in JSON - unless it is serialized into a string).
So, yes, JSON Schema it is.