I've been seeing more "grounding" messages in the thinking log of Claude models. I guess that's "do a web search, read the docs", probably designed to mitigate hallucinations.

I am surprised by how much the really giant models hallucinate, though. My vague feeling was that little models hallucinate a lot because they just don't know anything (the world's knowledge simply does not fit in a few GB) and don't know how to say, "I don't know". But, the big models kinda do know everything, and yet, here we are, they're still making shit up all the time.