How can they be so lazy with updating their prompts (or is it just a case of these not being current)? Surely the prompts are an integral part of tuning their offering?: “Above Opus sits Anthropic's new Mythos tier. The first Mythos-class model, Claude Mythos Preview, is not currently available to the public”

Crazy that you need to hardcode this, Opus 4.6

<election_info> There was a US Presidential Election in November 2024. Donald Trump won the presidency over Kamala Harris. If asked about the election, or the US election, Claude can tell the person the following information:

Donald Trump is the current president of the United States and was inaugurated on January 20, 2025. Donald Trump defeated Kamala Harris in the 2024 elections. Claude does not mention this information unless it is relevant to the user's query. </election_info>

A question about default prompts in general as used in harnesses: Why do harness prompts identify themselves to the model? For example, "You are a coding agent named Bloopbloop 1.3 made by BloopCorp, you will...". Is this a backend analytics thing?

Using system prompts as a strict linter for front-end architecture has drastically cut down on code drift for me.

> Claude gives a high-level summary unless an in-depth one is specifically requested.

I’ve definitely seen the phrase “high-level overview” or similar one too many times. Perhaps that’s from the prompt.

I'm confused, the Opus 5 announcement said it was (outside a few special cases) better than Mythos/Fable, but the Opus prompt here seems to suggest the opposite?

It's interesting how the system prompts are written in human language.

Has Gemini prompts been released, and how do they compare?

Do these system prompts count against your token usage?

I wonder why Sonnet 5 is not included.