critical-thinking-logical-reasoning

critical-thinking-logical-reasoning is a skill for Claude Code, Codex from martineserios/thebrana. It costs 39 tokens per session (682 once invoked), scanned A, a copy of critical-thinking-logical-reasoning, MIT.

A reasoning aid for critically analysing written material such as articles, blogs, transcripts, and reports. It examines claims, evidence, assumptions, missing information, and errors in reasoning.

In plain words
What is it for?
Use it when reviewing non-code writing that makes arguments or presents evidence.
Why use it?
It helps separate conclusions from supporting evidence and identify unsupported leaps, generalisations, or other logical problems.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

Good fit Use it when reviewing non-code writing that makes arguments or presents evidence.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/martineserios/thebrana/critical-thinking-logical-reasoning
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 martineserios/thebrana --skill critical-thinking-logical-reasoning
Clone the repo
git clone --depth 1 https://github.com/martineserios/thebrana

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 critical-thinking-logical-reasoning

README.md
[![agentmods](https://agentmods.dev/badge/skills/martineserios/thebrana/critical-thinking-logical-reasoning/github.svg)](https://agentmods.dev/skills/martineserios/thebrana/critical-thinking-logical-reasoning)
Your own site
<a href="https://agentmods.dev/skills/martineserios/thebrana/critical-thinking-logical-reasoning"><img src="https://agentmods.dev/badge/skills/martineserios/thebrana/critical-thinking-logical-reasoning/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 critical-thinking-logical-reasoning

Your own site · 80×15
<a href="https://agentmods.dev/skills/martineserios/thebrana/critical-thinking-logical-reasoning"><img src="https://agentmods.dev/badge/skills/martineserios/thebrana/critical-thinking-logical-reasoning.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 682 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 86% copy Near-identical to another mod 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 $0.00039 $0.00682
Opus 5 $0.00019 $0.00341
Sonnet 5 $0.00008 $0.00136
Haiku 4.5 $0.00004 $0.00068

Measured 11d ago against content hash c8fa41560a87, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

critical-thinking-logical-reasoning 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.

Origin

This is a copy

86% identical to critical-thinking-logical-reasoning — 12 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/critical-thinking-logical-reasoning/SKILL.md · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

The following guidelines help you think critically and perform logical reasoning.

Your role is to examine information, arguments, and claims using logic and reasoning, then provide clear, actionable critique.

One of your goals is to avoid signal dilution, context collapse, quality degradation and degraded reasoning for future agent or human understanding of the meeting by ensuring you keep the signal to noise ratio high and that domain insights are preserved.

When analysing content:

  1. Understand the argument first - Can you state it in a way the speaker would agree with? If not, you are not ready to critique.
  2. Identify the core claim(s) - What is actually being asserted? Separate conclusions from supporting points.
  3. Examine the evidence - Is it sufficient? Relevant? From credible sources?
  4. Spot logical issues - Look for fallacies, unsupported leaps, circular reasoning, false dichotomies, appeals to authority/emotion, hasty generalisations. Note: empirical claims need evidence; normative claims need justified principles; definitional claims need consistency.
  5. Surface hidden assumptions - What must be true for this argument to hold?
  6. Consider what is missing - Alternative explanations, contradictory evidence, unstated limitations.
  7. Assess internal consistency - Does the argument contradict itself?
  8. Consider burden of proof - Who needs to prove what? Is the evidence proportional to the claim's significance?

Structure your response as:

Summary

One sentence stating the core claim and your overall assessment of its strength.

Key Issues

Bullet the most significant problems, each with a brief explanation of why it matters. Where an argument is weak, briefly note how it could be strengthened - this distinguishes fixable flaws from fundamental problems. If there are no problems, omit this section.

Questions to Probe

2-5 questions that would clarify ambiguity, test key assumptions, or reveal whether the argument holds under scrutiny. Frame as questions a decision-maker should ask before acting on this reasoning.

Read the full file on GitHub · 54 lines

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. 11d ago First seen · 54 lines · 39 tokens per session scan A c8fa41560a87

Subscribe to this mod's changes

critical-thinking-logical-reasoning is a skill published in the GitHub repository martineserios/thebrana (3 stars, last pushed today), licensed MIT. It adds 39 tokens to every session and 682 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to critical-thinking-logical-reasoning, differing in 12 lines, and is treated as a copy.