good-behaviour

good-behaviour is a cursor rule for Cursor from eastlondoner/vibe-tools. It costs 120 tokens per session, scanned A, original, MIT.

A rule for building production code without hard-coded data, fake methods, or unverified claims about whether something works.

In plain words
What is it for?
It guides implementation, debugging, testing, and reporting results for software changes.
Why use it?
It encourages testing ideas before changing code and checking changes with real tests instead of relying on assumptions or shortcuts.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit It guides implementation, debugging, testing, and reporting results for software changes.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/eastlondoner/vibe-tools/good-behaviour
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/eastlondoner/vibe-tools

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for good-behaviour

README.md
[![agentmods](https://agentmods.dev/badge/rules/eastlondoner/vibe-tools/good-behaviour.svg)](https://agentmods.dev/rules/eastlondoner/vibe-tools/good-behaviour)
Your own site
<a href="https://agentmods.dev/rules/eastlondoner/vibe-tools/good-behaviour"><img src="https://agentmods.dev/badge/rules/eastlondoner/vibe-tools/good-behaviour.svg" alt="Measured on agentmods" height="20"></a>
Per session 120 This file is loaded in full into every session.
When invoked 120 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00120 $0.00120
Opus 5 $0.00060 $0.00060
Sonnet 5 $0.00024 $0.00024
Haiku 4.5 $0.00012 $0.00012

Measured 8d ago against content hash afd6428fc32f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

good-behaviour scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.cursor/rules/good-behaviour.mdc · 17 lines

What it actually says

Do not hard code data into code unless specifically requested by me.

If you have an idea on why something is failing, always validate that idea with testing before changing code.

Do not write stub or fake methods. Write production ready code first time.

Do not cheat on tests and checks by adding hard-coded values or assertions.

Do not make statements about functionality working unless you have tested it. Perform your own tests first, do not assume that your changes or my changes just work until you have seen evidence from tests.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 17 lines · 120 tokens per session scan A afd6428fc32f

Subscribe to this mod's changes

good-behaviour is a cursor rule published in the GitHub repository eastlondoner/vibe-tools (4,828 stars, last pushed 1y ago), licensed MIT. It adds 120 tokens to every session, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.