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principle-subtract-before-you-add

principle-subtract-before-you-add is a skill for Claude Code, Codex from edlng/agents. It costs 39 tokens per session (171 once invoked), scanned A, original, no licence file.

A change-planning rule for removing dead code, duplicate checks, and unused stubs before adding or rewriting code.

In plain words
What is it for?
It helps sequence additions, refactors, and rewrites around a simpler starting point.
Why use it?
It prevents new work from being built on unnecessary or redundant parts of the existing code.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

not rated 2repo 8d ago A scan 39 tokens no licence

Good fit It helps sequence additions, refactors, and rewrites around a simpler starting point.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/edlng/agents/principle-subtract-before-you-add
View source ↗ edlng/agents edlng.github.io
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.

Any agent
npx skills add edlng/agents --skill principle-subtract-before-you-add
Clone the repo
git clone --depth 1 https://github.com/edlng/agents

Made for: Claude Code, Codex.

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 principle-subtract-before-you-add

README.md
[![agentmods](https://agentmods.dev/badge/skills/edlng/agents/principle-subtract-before-you-add/github.svg)](https://agentmods.dev/skills/edlng/agents/principle-subtract-before-you-add)
Your own site
<a href="https://agentmods.dev/skills/edlng/agents/principle-subtract-before-you-add"><img src="https://agentmods.dev/badge/skills/edlng/agents/principle-subtract-before-you-add/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for principle-subtract-before-you-add

Your own site · 80×15
<a href="https://agentmods.dev/skills/edlng/agents/principle-subtract-before-you-add"><img src="https://agentmods.dev/badge/skills/edlng/agents/principle-subtract-before-you-add.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 171 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00039 $0.00171
Opus 5.5 $0.00016 $0.00068
Sonnet 5.5 $0.00008 $0.00034
Haiku 4.5 $0.00004 $0.00017

Measured 14d ago against content hash a273e3955fc3, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

principle-subtract-before-you-add 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 14d 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.

skills/universal/principle-subtract-before-you-add/SKILL.md · 18 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

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. 14d ago First seen · 18 lines · 39 tokens per session scan A a273e3955fc3

Subscribe to this mod's changes

principle-subtract-before-you-add is a skill published in the GitHub repository edlng/agents (2 stars, last pushed 8d ago), with no licence file. It adds 39 tokens to every session and 171 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-10-24.

Debugging
Related

principle-subtract-before-you-add compared with skills from other repositories

principle-subtract-before-you-add next to 6 skills from other repositories
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principle-subtract-before-you-addedlng/agentsSkill28d agononeA39Claude Code, Codex
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log-error-digestzebbern/claude-code-guideSkill4.7ktodayMITA71Claude Code, Codex
cwv-optimizeradobe/skillsSkill319todayApache-2.0A112Claude Code
ci-fixersipyourdrink-ltd/bernsteinSkill1.2ktodayApache-2.0A15Claude Code, Codex
diagnosing-missing-recordingsPostHog/posthogSkill41ktodaynoneA76Claude Code, Codex
loop-engineeringhuytieu/COG-second-brainSkill1.3k15d agoMITA63Claude Code