What is the role of a technical writer at Google?

In many job listings on Google Careers page, there are a lot of vacancies for the job of a technical writer at Google. The listing notes that technical writers are the link between developers, engineers, users and marketing associates. It says that you are supposed to get complex information as input and communicate it clearly & concisely without using technical or corporate jargon to explain.

Any idea what the role of a technical writer actually demands? What skill does one need to have? What qualifications? What experience?