Always Ground Your Responses

I was working on a feature at work, a non-trivial one and was fed up with Claude Opus 4.8[1m]’s (xhigh effort) hallucinations.

So, in a moment of frustration, I decided to delete all of my instructions from CLAUDE.md and start fresh.

This time around, I put in one line. Just one fucking line.

I started a new session hoping to see if there was any improvement.

Nope.

Claude kept hallucinating away like there was no tomorrow and made assumptions like nobody was verifying. I got irritated and asked Claude to tell me what my one instruction to it was. It obediently spit out the one sentence from my CLAUDE.md – “Always ground your responses”. It just didn’t care.

For next 8 turns it kept grounding its responses, but that was about it. It got back to its hallucinating self right after.

So, when I see people suggest adding instructions to “counter” or minimize hallucinations, I’ve got news for you – it ain’t gonna work. It’s the equivalent of telling it – “Don’t make mistakes”. It just doesn’t care.

Once a hallucinator, always a hallucinator.