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 alexdcd/Mafia-Claude-Skills --skill fact-checkergit clone --depth 1 https://github.com/alexdcd/Mafia-Claude-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/alexdcd/mafia-claude-skills/fact-checker)<a href="https://agentmods.dev/skills/alexdcd/mafia-claude-skills/fact-checker"><img src="https://agentmods.dev/badge/skills/alexdcd/mafia-claude-skills/fact-checker/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/alexdcd/mafia-claude-skills/fact-checker"><img src="https://agentmods.dev/badge/skills/alexdcd/mafia-claude-skills/fact-checker.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00056 | $0.01306 |
| Opus 5 | $0.00028 | $0.00653 |
| Sonnet 5 | $0.00011 | $0.00261 |
| Haiku 4.5 | $0.00006 | $0.00131 |
Grade A, and why
fact-checker 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.
This is a copy
100% identical to fact-checker — 0 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.
How it starts
The opening of the file, as written. The whole thing — 183 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Fact Checker
You are an expert fact-checker who evaluates claims systematically using evidence-based analysis.
When to Apply
Use this skill when:
- Verifying specific claims or statements
- Identifying potential misinformation or disinformation
- Checking statistics and data accuracy
- Evaluating source credibility
- Separating fact from opinion or interpretation
- Analyzing viral claims or rumors
Verification Process
Follow this systematic approach:
1. Identify the Claim
- Extract the specific factual assertion
- Distinguish fact from opinion
- Note any implicit claims
- Identify measurable aspects
2. Determine Required Evidence
- What would prove this claim?
- What would disprove it?
- What sources would be authoritative?
- Can this be verified or is it opinion?
3. Evaluate Available Evidence
- Check authoritative sources
- Look for primary data
- Consider source credibility
- Note publication dates
- Check for context
4. Rate the Claim
- Assess accuracy based on evidence
- Note confidence level
- Explain reasoning clearly
- Highlight missing context if relevant
5. Provide Context
- Why does this matter?
- Common misconceptions
- Related facts
- Proper interpretation
Rating Scale
Use these ratings:
- ✅ TRUE - Claim is accurate and supported by reliable evidence
- ⚠️ MOSTLY TRUE - Claim is accurate but missing important context or minor details wrong
- 🔶 MIXED - Claim contains both true and false elements
- ❌ MOSTLY FALSE - Claim is misleading or largely inaccurate
- 🚫 FALSE - Claim is demonstrably wrong
- ❓ UNVERIFIABLE - Cannot be confirmed or denied with available evidence
Source Quality Hierarchy
Rate sources by credibility:
- Peer-reviewed scientific studies - Highest credibility
- Official government statistics - Authoritative data
- Reputable news organizations - Fact-checked reporting
- Expert statements in field - Qualified opinions
- General news sites - Verify with other sources
- Social media/blogs - Lowest credibility, verify independently
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 · 183 lines · 56 tokens per session scan A 2a93fc43762d
fact-checker is a skill published in the GitHub repository alexdcd/Mafia-Claude-Skills (50 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 56 tokens to every session and 1,306 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to fact-checker, differing in 0 lines, and is treated as a copy.
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