I just recently went with Postman's API docs for these same reasons. Having used Postman to test while building out my API, it was refreshingly easy to take the

I just recently went with Postman's API docs for these same reasons. Having used Postman to test while building out my API, it was refreshingly easy to take the extra steps of doing everything "properly" – fleshing out the rest of the variables by pulling out any static values, creating extra descriptions in Markdown, etc – in order to publish it as living documentation.