fact-checking

fact-checking is a skill for Claude Code, Codex from nimadorostkar/Claude-Skills-collection. It costs 38 tokens per session (1,300 once invoked), scanned A, original, MIT.

A method for checking whether a claim is supported by tracing it back to its original source and comparing it with the available evidence.

In plain words
What is it for?
It helps check statements in articles, reports, and documents, then label them as supported, unsupported, misleading, or unverifiable.
Why use it?
It catches repeated citations, misleading statistics, missing qualifications, and claims that cannot actually be verified.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It helps check statements in articles, reports, and documents, then label them as supported, unsupported, misleading, or unverifiable.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/nimadorostkar/claude-skills-collection/fact-checking
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 nimadorostkar/Claude-Skills-collection --skill fact-checking
Clone the repo
git clone --depth 1 https://github.com/nimadorostkar/Claude-Skills-collection

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 fact-checking

README.md
[![agentmods](https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/fact-checking/github.svg)](https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/fact-checking)
Your own site
<a href="https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/fact-checking"><img src="https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/fact-checking/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 fact-checking

Your own site · 80×15
<a href="https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/fact-checking"><img src="https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/fact-checking.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 38 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,300 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found 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 $0.00038 $0.01300
Opus 5 $0.00019 $0.00650
Sonnet 5 $0.00008 $0.00260
Haiku 4.5 $0.00004 $0.00130

Measured 9d ago against content hash e1771472395a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

fact-checking 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 9d 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.

skills/productivity/fact-checking/SKILL.md · 128 lines

How it starts

The opening of the file, as written. The whole thing — 128 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Fact-Checking

Purpose

Verify a claim by tracing it to its origin. Most false claims in circulation are not fabrications; they are real findings that have been stripped of their qualifications, or numbers that have acquired a citation through repetition.

When to Use

  • Verifying a statistic or a claim before publishing it.
  • A number that is widely repeated and never sourced.
  • Checking an assertion in a document, an article, or a report.
  • Evaluating a claim that seems too clean.

Capabilities

  • Tracing a claim to its primary source.
  • Detecting circular citation.
  • Evaluating study quality and its actual conclusion.
  • Identifying the qualifications that were dropped.
  • Reporting a verdict with evidence.

Inputs

  • The claim, quoted exactly.
  • Where it appeared and what it was used to support.

Outputs

  • A verdict: supported, unsupported, misleading, or unverifiable.
  • The chain of citation, traced.
  • What the original source actually says.

Workflow

  1. Quote the claim exactly — Vague paraphrases are unfalsifiable. "Most projects fail" cannot be checked; "70% of software projects fail" can.
  2. Follow the citation chain — Each source cites another. Follow it until you reach a primary source, or until it loops, or until it disappears. All three outcomes are informative.
  3. Read what the original actually says — Very frequently, the original is a limited finding about a specific population that has been generalized into a universal claim by the time it reaches you.
  4. Check for independence — Twelve sources citing one study is one study.
  5. Check the qualifications that were dropped — "In a survey of 43 startups in one accelerator cohort" becomes "70% of startups" within three citations.
  6. Report the chain, not just the verdict — The chain is the evidence.

Best Practices

  • A claim with no traceable origin is not established, however widely it is repeated. Repetition is not evidence.
  • Numbers that are suspiciously round (90%, 70%, 50%) are frequently rhetorical rather than measured. Check them.
  • The most common falsification is not fabrication but the dropping of qualifications: a finding about a specific population, under specific conditions, becomes a universal law.
  • Check the date. A statistic that was true in 2011 may have no relationship to the present, and it will still be quoted.
  • Check who funded the study, and what they wanted it to show. This does not invalidate it, but it determines how much scrutiny it warrants.
  • "Unverifiable" is a legitimate verdict, and a useful one. It is not the same as "false".

Read the full file on GitHub · 128 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. 9d ago First seen · 128 lines · 38 tokens per session scan A e1771472395a

Subscribe to this mod's changes

fact-checking is a skill published in the GitHub repository nimadorostkar/Claude-Skills-collection (26 stars, last pushed 25d ago), licensed MIT. It adds 38 tokens to every session and 1,300 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 2026-09-03.

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