记录WCF接口的最佳方法?

So I'm using WCF, and want to document my interface(s) and services to give to another company for an internal app. What's the best way to document those interfaces? I'd prefer having the documentation inline with the code, and then have something prettify to output HTML, but am not sure if there's a recommended way to do it.So I'm using WCF, and want to document my inter