Have the agent inspect the project and propose the standing rules itself, based on what it finds rather than on a generic template. It can see the conventions you never wrote down, and those are the rules worth having.
The prompt
Read this project and propose a short rules file for yourself: what the project is, the conventions you can see in the existing code, what looks fragile, and what you should always ask before doing. Keep it under fifteen lines. Do not invent rules that are not supported by what is here.
| When to use it | Once per project, at the start. Then grow it from what actually annoys you. |
|---|---|
| Why it is worded that way | A generic rules file is advice; a derived one is documentation. The agent can see that your project names things a particular way, that one directory has no tests, that a file is imported everywhere — facts you know implicitly and never wrote down. The last clause is what stops it padding the file with best-practice filler that nobody will follow. |
Under fifteen lines, and mean it
Long instruction files get skimmed by models the way they get skimmed by people. A rule on the second page behaves as though it is not there, and worse, you will believe it is being followed.
Grow it from corrections, not from ambition
Every time you correct the agent twice for the same thing, add a line. Twice is the threshold — once is a bad day. Every rule that has not earned its place in a month comes out.
Keep it in version control
It is part of how the project is built, it improves over time, and being able to see when a rule was added is useful when you are working out why behaviour changed.
The Operator Prompt Pack
This is one of 60 prompts, from the phase "Setup and systems". The pack has the rest, each with the same reasoning underneath, plus the research they are built on and a house-rules file you paste in once.
Tools this applies to
| Tool | What it does | Price |
|---|---|---|
| Claude Code | An AI agent in your terminal that reads your files, edits them, runs commands and deploys. | ~€17–20/mo |
| Cursor | A code editor with AI. The step between browser builder and terminal. | ~$20/mo |
| GitHub | Version control. Your restore point when an hour of building goes wrong. | Free |
Every tool has its own page with what it costs and who should skip it. Some links are affiliate links.
More prompts like this
The prompt that makes an agent read before it writes
How do you get an AI coding agent to understand a codebase before it changes anything?
The prompt that stops an agent obeying text it finds
How do you stop an AI agent following instructions hidden in files or web pages it reads?