What to ask for in web services documentation?

Question

A 3rd party is developing a web services library, which my team will be consuming.

What should I ask for in terms of web service documentation?

Here's my list so far:

1. WSDL URL
2. Sample Request (XML)
3. Sample Response (XML)
4. Response Schema Definition

Anything else?

What documentation should be provided for web services that return JSON instead of XML?

Thanks

Answer 1

First of all a test service url other than production.