Fact Checker

Fact Checker

Automated fact-checking with confidence scoring and source attribution.

Use when verifying claims, checking article accuracy, or fact-checking content before publishing.

Requirements

• web_search tool access
• No API keys needed

Instructions

1. Extract claims from the provided text. List each claim separately. Skip opinions and subjective statements — only fact-check factual assertions.

2. Search for evidence using web_search for each claim. Search for the core factual assertion, not the full sentence. Run 2-3 searches with different phrasings if initial results are inconclusive.

3. Evaluate sources with this hierarchy:

   • 🥇 Official sources (government, organizations cited in the claim)
   • 🥈 Peer-reviewed research, established wire services (AP, Reuters)
   • 🥉 Major news outlets with editorial standards
   • ⚠️ Blogs, social media, opinion pieces (note as weak evidence)

4. Assign verdict to each claim:

   Verdict	Confidence	Criteria
   ✅ Verified	90-100%	Multiple reliable sources confirm
   ⚠️ Partially True	50-89%	True with caveats or missing context
   ❌ False	0-29%	Contradicted by reliable sources
   🔍 Unverifiable	N/A	Insufficient sources to determine

5. Output format:

   ## 🔍 Fact Check Report
   **Source:** [article/text title]
   **Date checked:** YYYY-MM-DD
   
   ### Claim 1: "[exact claim text]"
   **Verdict:** ✅ Verified (95%)
   **Evidence:** [2-3 sentence summary]
   **Sources:**
   - [Source name](URL) — [key finding]
   - [Source name](URL) — [key finding]
   
   ### Summary
   | # | Claim | Verdict |
   |---|-------|---------|
   | 1 | [short claim] | ✅ Verified |
   | 2 | [short claim] | ❌ False |
   **Overall accuracy: X/Y claims verified**
   

Edge Cases & Troubleshooting

• Date-sensitive claims: Note when the info was last verified. Facts about statistics, rankings, or prices change frequently.
• Ambiguous claims: If a claim can be interpreted multiple ways, check the most charitable interpretation first, then note caveats.
• No sources found: Mark as 🔍 Unverifiable — absence of evidence is not evidence of absence.
• Conflicting sources: Report the conflict explicitly. Note which sources are more authoritative and why.
• Satire/parody: Flag if the original source appears to be satirical.

Security Considerations

• Never fabricate sources or URLs — only cite actually found results.
• Don't present search snippets as verified facts; always cross-reference.
• Disclose limitations transparently in the report.