Looking for an overview of YouTube API caption data. Trying to find how many videos from a set have CCs (autogenerated or otherwise)

I'd like to take a set of YT videos and, from the metadata, determine:

1. how many of them have closed captioning
2. whether it's autogenerated closed captioning
3. what language the captions are in

I know there's contentDetails.caption, but in the set I'm looking at, I get "false" for all videos while several of them do in fact have autogenerated closed captioning. This leads me to wonder the best way to answer these questions.

Bit of an API newbie, so sorry if this is a basic question.

Thanks.