Claude Code thinking skills

Install

Manual install

/plugin marketplace add tjboudreaux/cc-thinking-skills
/plugin install thinking-skills@thinking-skills-marketplace

This is third-party code. Review the repository files before installing.

What it does

The set gives the agent 28 portable skills, each defining a clear reasoning procedure for one mental model. Diagnosis skills include the scientific method, five whys, the Kepner-Tregoe method and systems thinking. Decision skills include reversibility, opportunity cost, probabilistic thinking, second-order effects and steel-manning. Creation and improvement skills include first principles, TRIZ, via negativa, thought experiments and jobs-to-be-done. Risk and execution skills include the pre-mortem, red team, margin of safety, theory of constraints and the OODA loop. A separate router skill helps pick the right model or honestly return that none is needed: it outputs nothing, one primary skill, or up to three complementary ones. Each skill states when to use it and when not to. It installs as a Claude Code plugin, via npx skills or by copying folders, and also works in Copilot, Codex, Cursor and other Agent Skills-compatible tools.

Who it is for. For product managers, founders and developers who want a ready toolkit of structured reasoning to work through problems with an agent.

Example request

Use thinking-pre-mortem to find where our launch plan could fail

Limitations

The skills give a reasoning procedure, not a finished answer: output quality depends on the inputs and the agent's judgment. By the project's own audit all skills are manual-only, there is no automatic trigger mode, and the authors claim no measured accuracy gain and ask not to present provisional numbers as a proven result. Some checks and evals in the repository need Node.js and a separate CLI. MIT licensed.

How to disable. Remove the plugin via /plugin, or delete the skill folders from the agent's skills directory, for example .claude/skills/ or ~/.claude/skills/.

Security check

• The skills consist only of instructions and reasoning procedures

README in short

The README presents a catalog of 28 portable structured-thinking skills for Claude Code, Copilot, Codex, Cursor and other compatible tools. The skills are grouped by task: diagnosis, decisions, creation and improvement, risk and execution, plus a router for choosing the right model. Installation is via npx skills, as a Claude Code plugin with /plugin install thinking-skills@thinking-skills-marketplace, or by copying folders from skills/. The README asks you to read the catalog audit before any performance claims: all skills are manual-only, there is no measured accuracy gain, and a provisional figure sits below the utility threshold. MIT licensed.

SKILL.md

---
name: thinking-model-router
description: When unsure which thinking skill fits, map domain and problem type, then return NONE or one primary skill by default (at most three complementary).
disable-model-invocation: true
---

# Model Router

**Core rule:** Prefer NONE or one primary skill. Route by mechanism fit, not habit. Combine only when roles are distinct and necessary.

## When to Use

- The right thinking skill is unclear and you would otherwise guess or stack tools.
- Several catalog skills seem plausible and you need a single primary (or explicit NONE).
- High-stakes work where a wrong frame is costly and a quick domain by type match helps.

## When NOT to Use

- The match is already known or obvious, invoke that skill directly.
- The task is routine implementation with no analytical unknown, reason directly (NONE).

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