grug-brained-dev_avoid-premature-optimization

grug-brained-dev_avoid-premature-optimization is a cursor rule for Cursor from colchuck-ai/ai-resource-manager. It costs 224 tokens per session, scanned A, original, GPL-3.0.

A coding rule that says performance improvements should wait until real performance problems have been measured.

In plain words
What is it for?
It guides decisions about when to optimise code and encourages addressing observed performance issues first.
Why use it?
It helps avoid spending time on speculative optimisations that may make code harder to understand without solving an actual problem.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit It guides decisions about when to optimise code and encourages addressing observed performance issues first.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/colchuck-ai/ai-resource-manager/grug-brained-dev_avoid-premature-optimization
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/colchuck-ai/ai-resource-manager

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 grug-brained-dev_avoid-premature-optimization

README.md
[![agentmods](https://agentmods.dev/badge/rules/colchuck-ai/ai-resource-manager/grug-brained-dev_avoid-premature-optimization.svg)](https://agentmods.dev/rules/colchuck-ai/ai-resource-manager/grug-brained-dev_avoid-premature-optimization)
Your own site
<a href="https://agentmods.dev/rules/colchuck-ai/ai-resource-manager/grug-brained-dev_avoid-premature-optimization"><img src="https://agentmods.dev/badge/rules/colchuck-ai/ai-resource-manager/grug-brained-dev_avoid-premature-optimization.svg" alt="Measured on agentmods" height="20"></a>
Per session 224 This file is loaded in full into every session.
When invoked 224 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 unknown 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 $0.00224 $0.00224
Opus 5 $0.00112 $0.00112
Sonnet 5 $0.00045 $0.00045
Haiku 4.5 $0.00022 $0.00022

Measured 7d ago against content hash ff3164fd7a26, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

grug-brained-dev_avoid-premature-optimization 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 7d 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.

.cursor/rules/grug-brained-dev/grug-brained-dev_avoid-premature-optimization.mdc · 42 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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. 7d ago First seen · 42 lines · 224 tokens per session scan A ff3164fd7a26

Subscribe to this mod's changes

grug-brained-dev_avoid-premature-optimization is a cursor rule published in the GitHub repository colchuck-ai/ai-resource-manager (23 stars, last pushed 5mo ago), licensed GPL-3.0. It adds 224 tokens to every session, about $0.0011 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.

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