Agents follow rules that are easy to apply in the next edit. They skim rules that read like a manifesto.
One concern
“UI craft” and “SQL migrations” should not share a file. Split them. Name the file after the concern.
Write like a checklist
Prefer:
- Never ship lorem or “Welcome to your app.”
- Buttons start with a verb.
Over:
- A five-paragraph philosophy of design.
Scope with globs
A visual rule on **/*.{tsx,css} will not nag the agent during a schema change. An always-on voice rule can stay global because it is small.
Put examples in the negative
“Do not use purple-on-black AI gradients” is more useful than “make it beautiful.” Beauty is not a constraint. A forbidden pattern is.
Keep a kill list
If a rule has not changed an edit in a month, delete it. Dead rules still occupy context.
Test it
Start a fresh chat: “Add a settings page.” If the agent ignores your type and copy rules, the rule is too long, always-on among too many others, or written as inspiration instead of instruction.