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-circle-of-competencegit 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-circle-of-competence)<a href="https://agentmods.dev/skills/tjboudreaux/cc-thinking-skills/thinking-circle-of-competence"><img src="https://agentmods.dev/badge/skills/tjboudreaux/cc-thinking-skills/thinking-circle-of-competence/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-circle-of-competence"><img src="https://agentmods.dev/badge/skills/tjboudreaux/cc-thinking-skills/thinking-circle-of-competence.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
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 | $0.00039 | $0.00660 |
| Opus 5 | $0.00019 | $0.00330 |
| Sonnet 5 | $0.00008 | $0.00132 |
| Haiku 4.5 | $0.00004 | $0.00066 |
Grade A, and why
thinking-circle-of-competence 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 12d 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 — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Circle of Competence
Treat competence as an evidence boundary, not self-image. Answer only when grounded; otherwise fetch, mark uncertainty, or abstain. The failure mode is a fluent fabrication treated as fact.
When to Use
- About to assert a specific fact (API, path, number, config, version behavior) without a citable source from this session.
- The claim is about this codebase or system and you have not read or run the relevant artifact.
- Pattern reconstruction would sound complete but is unconfirmed.
- Cost of a wrong confident answer is material (security, data, irreversible action, trust).
When NOT to Use
- Claim is grounded in something you read, ran, or can cite this session, or is stable universal knowledge — answer without false humility.
- Error cost is trivial and reversible and you will flag the claim as unverified.
- Grounding is one cheap fetch away — fetch first; abstention is not an excuse to skip a check.
- User explicitly wants labeled brainstorming or hypotheticals.
Procedure
- Name the claim. Isolate the assertion that would be treated as fact.
- Classify the zone.
- Grounded: citeable session source (read/run) or stable non-version-specific knowledge.
- Partial: general shape known; version/repo/config detail unconfirmed.
- Ungrounded: would invent a concrete value with no source.
- Size wrongness cost. If high-stakes (security, data loss, irreversible ops), treat Partial as Ungrounded until verified.
- Act by zone.
- Grounded → answer; cite when useful; do not hedge verified facts.
- Partial → cheap fetch then answer; else answer only with explicit uncertainty and a check path.
- Ungrounded → fetch if possible; else ask or abstain with what would enable an answer. Never invent.
- Refuse competence creep. Adjacent code, prior versions, or general capability do not ground the unread target.
- Stop. Emit answer, fetch request, or abstention. Do not round "probably" to a flat assertion.
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.
- 12d ago First seen · 58 lines · 39 tokens per session scan A 0c740956cb49
thinking-circle-of-competence is a skill published in the GitHub repository tjboudreaux/cc-thinking-skills (1,306 stars, last pushed 1mo ago), licensed MIT. It adds 39 tokens to every session and 660 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.
Other skills, from other repositories
forensic-read
Read any document the way a detective reads a witness statement — surface what it is NOT saying. Unlike a summarizer (which tells you what a text says), this skill exposes the subtext: hedging and weasel words, conspicuous omissions, buried leads, frequency tells, tone shifts, and non-answers. Use it on earnings…
pre-mortem
Find what will kill a plan before it's committed to — by assuming it already failed and working backwards to the causes. Based on Gary Klein's pre-mortem technique. Unlike generic "what are the risks?" brainstorming, this skill imagines a specific, vivid failure six months out, reasons back to the most likely causes…
second-order
Reason past the obvious, first-order consequence to the second-, third-, and long-tail effects everyone else stops short of. Where most analysis says "X causes Y", this skill asks "and then what?" — mapping the cascade, surfacing the non-obvious winners and losers, the reflexive responses, and the effects that only…
foundation-models
On-device LLM integration using Apple's Foundation Models framework. Use when implementing AI text generation, structured output, or tool calling.
analytics-interpretation
Interpret app metrics and make data-driven decisions. Covers DAU/MAU, retention, LTV, ARPU, App Store Connect analytics, AARRR funnel analysis, cohort analysis, and diagnostic decision trees. Use when user wants to understand their metrics, diagnose problems, or build a data-driven growth plan.
app-namer
Turn an app idea into validated, App-Store-ready name candidates. Use when the user says "name my app", "what should I call it", "app name ideas", "help me name this app", "is this name available", or needs to pick a brandable, ownable name before reserving it in App Store Connect.