metapromptlisted

# Metaprompt A prompt written by feel, without checking what actually works for the specific model and harness that will run it, tends to either under-specify (missing a technique that model responds well to) or over-specify (re-stating things the harness already guarantees, which dilutes attention). This skill treats prompt-writing as a small research task with three required inputs, not a one-shot creative exercise. ## When to use this - Writing a prompt, system message, or agent instructions meant to run on a specific model inside a specific harness — most valuably when that combination differs from the one currently running this conversation (you can't rely on your own default behavior as a stand-in for how the target will behave). - The user asks to "write a prompt for X model" or "write the system prompt for this agent" and names or implies a target model/harness. ## Instructions ### 1. Get all three required inputs - **Goal** — what should the resulting prompt make the model do? - **Target model** — the specific model/family (e.g. "Claude Opus 4.8," "GPT-5.2," "Gemini 3 Pro"). Techniques differ meaningfully even within one vendor's lineup — don't accept "an LLM" as an answer. - **Target harness** — what will actually run this prompt: Claude Code, Codex CLI, a custom agent loop, the raw API, a chat UI, something else. This determines what the harness already handles for you vs. what the prompt must spell out. If any is missing or ambiguous, ask be