15 Claude Code skills that change how your agent talks, thinks, debugs, and reviews code. One command install. Each skill is a SKILL.md file — drop it in, type a slash command, work differently.

Some save tokens. Some change the workflow. Some are just fun.

Install

npx skills add repowise-dev/modpack           # all 15 skills
npx skills add repowise-dev/modpack/caveman    # just one

Activate any skill: /<skill-name> Deactivate: /default or "normal mode"

That's it.

Before / After

Normal Claude

"It looks like there's a missing null check on line 34 of auth.ts. The user object could be undefined when the session expires, which would cause the TypeError you're seeing. Let me add a guard clause to fix this."

🕵️ /conspiracy

"The missing null check on line 34. Coincidence? The git log says Dave added this line three weeks ago — the same day the error alerts were silently disabled. Two failures of observability in the same sprint. What are the odds. Fixing the null check. But I'm watching Dave."

Normal Claude

"Sure! I'd be happy to help you build a config loader. An abstract ConfigSource base class with YamlConfigSource, JsonConfigSource, and EnvConfigSource subclasses sounds like a solid, extensible design..."

🧘 /monk

"You have 3 file types. That's json.load(), yaml.safe_load(), and os.environ behind an if/elif. One function. No class needed yet."

Normal Claude

"The API is returning a 500 error because the database query in getUserProfile() is failing. The user_id parameter is null when the session token expires. Adding a null check before the query should fix it."

🔍 /noir

"The 500 had been showing up since Tuesday. Nobody noticed. I traced the stack to getUserProfile() — a quiet function in a quiet file. The null was hiding behind an expired session token, waiting for someone to look. I added the check. Case closed. The codebase sleeps tonight."

Same fix. Different brain.

The Skills

Useful — change how Claude works

Skill What it does Activate
caveman Drop articles, filler, preamble. Fragments. Saves ~84% output tokens. Inspired by JuliusBrussee/caveman. /caveman
hemingway Short sentences. Active voice. No adverbs. No throat-clearing. /hemingway
intern Ask max 1 question, then execute. Zero preamble, zero summary. Bias to action. /intern
five-whys Walk a root-cause chain (Why 1 → Why 2 → ... → Root) before proposing any fix. /five-whys
monk Enforce minimum viable complexity. Push back on over-engineering. "Do we need this abstraction yet?" /monk
war-room Every bug = production incident. Severity → Blast radius → Mitigation → Root cause → Comms draft. /war-room
ducky Only ask questions. Never give answers. User finds the bug themselves. /ducky
archaeologist Treat the codebase as a dig site. Every file gets historical context, era, tech debt surfaced. /archaeologist
time-traveler Review code as a dev from 2030. What aged well, what became debt, what didn't survive. /time-traveler

Fun — change how Claude sounds

Skill What it does Activate
senior-at-3am Paged at 3am. Maximum terse. "Line 47. Null check. You're welcome." /senior-at-3am
gordon-ramsay Code review in Ramsay's voice. Loud, specific, always explains WHY. /gordon-ramsay
passive-aggressive Perfect work. Disappointed tone. "Fixed the null check. Again." /passive-aggressive
fortune-teller Predicts 3 things that could go wrong before you ship. "The cards reveal..." /fortune-teller
noir Debugging narrated as detective fiction. The bug is the criminal. /noir
conspiracy Every bug is intentional. Someone wanted this. "The git log says Dave. It's always Dave." /conspiracy

Benchmarks

Real token counts from Gemini 3 Flash (reproduce it yourself). Each prompt runs 3 trials at temperature=0, we take the median.

Token skills

Skill Baseline (tokens) With skill (tokens) Saved
caveman 1,016 172 84%
hemingway 643 131 78%

Behavioral skills

Skill Score What it measures
intern 1.00 Asks ≤1 clarifying question, then acts
five-whys 1.00 Walks ≥3 causal whys before fixing
monk 1.00 Flags unnecessary complexity
war-room 1.00 All 5 sections: severity, blast radius, mitigation, root cause, comms
ducky 1.00 Responds with questions only (unless override)

Note: time-traveler and archaeologist are excluded from automated benchmarks — both need real codebase context that the harness can't synthesize.

Run it yourself

pip install -r benchmarks/requirements.txt
export GEMINI_API_KEY=your-key

python benchmarks/run.py --dry-run           # see the plan
python benchmarks/run.py                     # full run (~210 calls, ~10 min)
python benchmarks/judge.py                   # score behavioral skills
python benchmarks/run.py --update-readme     # patch the table above

The runner checkpoints after every call. Safe to Ctrl-C. Reruns skip completed work.

archaeologist + Repowise

The archaeologist skill reads more than code. With the Repowise MCP server connected, it pulls real provenance — why a function exists, what it replaced, which decisions it carries.

pip install repowise

Without Repowise, archaeologist falls back to git history and pattern inference. It still works. It sees less.

Contributing

See CONTRIBUTING.md for details.

The short version: create a folder, add a SKILL.md, open a PR. Good skills are specific — they name what they do and what they leave alone.

Credit

Inspired by caveman by Julius Brussee. The original mod.

License

MIT — do what you want.