caveman

caveman is a skill for Claude Code, Codex from johnefemer/skillfish. It costs 53 tokens per session (1,217 once invoked), scanned C, original, no licence file.

A communication style that makes an agent use much shorter wording while keeping technical details accurate. It offers several intensity levels and supports many coding agents.

In plain words
What is it for?
It is for changing response style in Claude Code, Cursor, Copilot, Gemini CLI, and other supported agents.
Why use it?
It reduces the amount of text in agent responses when concise output is preferred.

Skill for Claude CodeCodex

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

Good fit It is for changing response style in Claude Code, Cursor, Copilot, Gemini CLI, and other supported agents.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/johnefemer/skillfish/caveman
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 johnefemer/skillfish --skill caveman
Clone the repo
git clone --depth 1 https://github.com/johnefemer/skillfish

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 caveman

README.md
[![agentmods](https://agentmods.dev/badge/skills/johnefemer/skillfish/caveman/github.svg)](https://agentmods.dev/skills/johnefemer/skillfish/caveman)
Your own site
<a href="https://agentmods.dev/skills/johnefemer/skillfish/caveman"><img src="https://agentmods.dev/badge/skills/johnefemer/skillfish/caveman/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 caveman

Your own site · 80×15
<a href="https://agentmods.dev/skills/johnefemer/skillfish/caveman"><img src="https://agentmods.dev/badge/skills/johnefemer/skillfish/caveman.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,217 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. 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 $0.00053 $0.01217
Opus 5.5 $0.00021 $0.00487
Sonnet 5.5 $0.00011 $0.00243
Haiku 4.5 $0.00005 $0.00122

Measured 2mo ago against content hash 776c31fa2a53, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade C, and why

caveman scanned grade C with 1 finding 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 2mo 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.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

- **Destructive operations** — `DROP TABLE`, `rm -rf`, irreversible actions
skills/caveman/SKILL.md · 131 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. 2mo ago First seen · 131 lines · 53 tokens per session scan C 776c31fa2a53

Subscribe to this mod's changes

caveman is a skill published in the GitHub repository johnefemer/skillfish (4 stars, last pushed 4d ago), with no licence file. It adds 53 tokens to every session and 1,217 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Related

caveman compared with skills from other repositories

caveman next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
cavemanjohnefemer/skillfishSkill44d agononeC53Claude Code, Codex
imagegenopenai/codexSkill133kyesterdayApache-2.0A113Codex
playwright-climicrosoft/playwrightSkill99kyesterdayApache-2.0A19Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginnersSkill79k4d agoMITA200Claude Code, Codex
systematic-debuggingobra/superpowersSkill313k3d agoMITA21Claude Code
next-cache-components-adoptionvercel/next.jsSkill143kyesterdayMITA95Claude Code
next-partial-prefetching-adoptionvercel/next.jsSkill143kyesterdayMITA103Claude Code