Claude Code Thinking Skills is a catalogue of 28 portable skills that give coding agents structured procedures for reasoning about decisions, diagnosis, risk, strategy, and related problems. It is intended for Claude Code, GitHub Copilot, Codex, Cursor, and other tools that support Agent Skills.
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.
npx skills add tjboudreaux/cc-thinking-skills --skill thinking-reversibilitygit clone --depth 1 https://github.com/tjboudreaux/cc-thinking-skillsWrote 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.
[](https://agentmods.dev/skills/tjboudreaux/cc-thinking-skills/thinking-reversibility)<a href="https://agentmods.dev/skills/tjboudreaux/cc-thinking-skills/thinking-reversibility"><img src="https://agentmods.dev/badge/skills/tjboudreaux/cc-thinking-skills/thinking-reversibility/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.
<a href="https://agentmods.dev/skills/tjboudreaux/cc-thinking-skills/thinking-reversibility"><img src="https://agentmods.dev/badge/skills/tjboudreaux/cc-thinking-skills/thinking-reversibility.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Excessive Agency · line 56 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00034 | $0.00728 |
| Opus 5 | $0.00017 | $0.00364 |
| Sonnet 5 | $0.00007 | $0.00146 |
| Haiku 4.5 | $0.00003 | $0.00073 |
Grade A, and why
thinking-reversibility 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 11d 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.
How it starts
The opening of the file, as written. The whole thing — 57 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Reversibility
Core rule: match process depth to undo cost. Most decisions are cheaper to reverse than they look; irreversible ones deserve deliberation and staged commitment.
When to Use
- Uncertain how much analysis a decision deserves (tech, process, product, org)
- Tempted to committee a low-blast-radius choice, or to rush a high-lock-in one
- Can redesign the move (pilot, flag, abstraction, time-box) to lower undo cost
- High-stakes choice where acting vs waiting have asymmetric recovery profiles
When NOT to Use
- Already classified this session—decide at matched depth; do not re-label forever
- Trivial two-way calls (names, local refactors) where deciding is cheaper than classifying
- Externally forced move with no optionality (hard deadline, contract, regulation)
- Correctness gates (security, data integrity) that need the right answer, not speed theater
Procedure
- Name the decision and undo path. State what would be committed and the concrete reverse move (rollback, migrate back, revoke, re-hire, re-contract).
- Score reversibility. Assess technical effort, time, money, reputation, dependents, and learning lost if reversed. Classify:
- Type 2: undo in days, low cost → decide fast
- Type 1.5: undo in weeks, moderate cost → light structure + monitor
- Type 1: months or not realistically undoable → deliberate
- Asymmetric downside / recovery. For Type 1 or 1.5:
- Acting wrong: downside, recoverable?, recovery cost
- Not acting: what permanently closes (window, exclusivity, path lock)
- Rule: recoverable acting downside + permanent inaction loss → staged commit over indefinite delay; catastrophic or third-party harm → refuse or redesign first
- Option-preserving redesign. Prefer pilots, feature flags, interfaces, versioning, time-boxed vendor terms, or strangler slices that convert Type 1 surface into Type 2 experiments. Deliberate only the residual irreversible core.
- Match process and commit. Type 2: pick a reasonable option, ship, monitor. Type 1: document assumptions, argue the opposing case, surface to owner if stakes require it. Stop once class and commitment depth are set—do not re-analyze without new undo-cost evidence.
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.
- 11d ago First seen · 57 lines · 34 tokens per session scan A 674f597cbc2f
thinking-reversibility is a skill published in the GitHub repository tjboudreaux/cc-thinking-skills (1,300 stars, last pushed 1mo ago), licensed MIT. It adds 34 tokens to every session and 728 once invoked, about $0.0002 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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