It’s just data

Doctrine of Minimum Necessary Disclosure

Ryan Tomayko Schemas can be useful when placed far enough up the stack. (i.e., don’t bake schema and language binding in at the protocol level.) Just because WSDL sucks doesn’t mean describing representations using some formal schema is a bad idea

The right question is not “schemas: yes or no?”.

The right question is: what is the absolute minimum you can require in order to achieve meaningful interop?

HTML’s A element is a good example.  XSD used in the context of WSDL is a bad example.

See also: loose coupling.