I ended up throwing the README at an LLM and it gave me a much simpler and clearer explanation. Copying the bits of an explanation that helped me:

> The problem it’s trying to solve is that generating valid SQL doesn’t necessarily produce the right answer. An AI might find a column called revenue, but still choose the wrong dataset or misunderstand whether that figure includes things like refunds. Auto Ontology adds information about what the data means to help it make those decisions.

and then the one paragraph summary at the end:

> My reading: it’s a database chat application built around a reusable catalogue of business meaning. The question worth testing is whether that catalogue makes answers measurably more correct—and how much human work it takes to get the definitions right.