Ask HN: How Do Tech Companies Evaluate Docs Quality?

Recently, I am playing around the Android SDK and docker. However, I found the docs site quality of Android SDK is lousy. It's hard to follow. I need to spend a long time to understand the concept.

I just wonder how tech companies evaluate the quality of doc sites? How do they know where developers get stuck? How do they know which part is unclear?

Anyone here managing the doc site?