Drawing inspiration from this... has anyone experimented with ways to make their API docs more readable by agents?

Sure, llms.txt is a convention for this.

Compare https://docs.firetiger.com with https://docs.firetiger.com/llms.txt and https://docs.firetiger.com/llms-full.txt for a realy example.

Yup: https://github.com/yagmin/lasso