Not Claude but ChatGPT - I asked it to pipe down on exactly that kind of response. And it did.

GPT-5 ends every single response with something like.

> If you’d like, I can demonstrate…

or

> If you want…

and that's /after/ I put in instructions to not do it.

I've done this in my Claude settings, but it still doesn't seem that keen on following it:

> Please be measured and critical in your response. I appreciate the enthusiasm, but I highly doubt everything I say is “brilliant” or “astute”, etc.! I prefer objectivity to sycophancy.

Yes, ChatGPT can do this, more or less.

Yet I'll tell it 100 times to stop using em dashes and it refuses.