It seems to basically one-shot off of the top X search results. If you ask it a spec I would expect it to be quite reliable. If you try to use it for anything with nuance it will typically fall on its face.

It has at least improved with the second category recently that it seems to be more right than wrong. But it still tends to work your query into whatever results it got, which makes it downright dangerous for when people are doing searches on health-related information.