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$ agentstack add skill-isvlasov-rageatc-oss-verifying-claims ✓ scanned · ✓ verified — works with Claude Code, Cursor, and more.
Security review
✓ PassedNo issues found. Passed automated security review. · v0.1.0 How review works →
- ✓ Prompt-injection patterns
- ✓ Secret / credential exfiltration
- ✓ Dangerous shell & filesystem operations
- ✓ Untrusted network calls
- ✓ Known-malicious package signatures
What it can access
- ✓ Network access No
- ✓ Filesystem access No
- ✓ Shell / process execution No
- ✓ Environment & secrets No
- ✓ Dynamic code execution No
From automated source analysis of v0.1.0. “Used” means the capability is present in the source — more access means more to trust, not that it’s unsafe.
About
Verifying Claims
Purpose
Systematically verify factual claims in both AI-generated and human-generated content using established journalism standards, academic source evaluation frameworks, and AI-specific hallucination detection methods.
This skill enables rigorous fact-checking through:
- Claim categorisation (factual/interpretive/opinion)
- Multi-source triangulation and cross-referencing
- Source quality assessment using established criteria
- AI hallucination detection (semantic entropy, extrinsic checks)
- Conflicting source resolution protocols
- Transparent confidence calibration
When to Use This Skill
Primary triggers:
- User requests fact-checking, claim verification, or accuracy assessment
- Reviewing research outputs or AI-generated content for reliability
- Validating sources cited in documents or reports
- Detecting potential hallucinations in AI responses
- Resolving conflicting information across sources
- Assessing information quality before relying on it
Integration contexts:
- Used by researcher-agent to validate research findings
- Used by critic-agent to assess factual accuracy in artefacts
- Used by producer-agent to ensure reliable sourcing
- Used as verification gate before finalising deliverables
Inputs Required
Always required:
- [ ] Claim(s) to verify - Specific statements requiring fact-checking
- [ ] Verification mode - Retrospective (sources provided) OR Proactive (find sources)
Context-dependent:
- [ ] Provided sources (for retrospective verification) - Documents, research, context materials
- [ ] Domain context - Field-specific considerations (medical, legal, technical, etc.)
- [ ] Risk level - Significance of accuracy (high-stakes decisions vs casual inquiry)
- [ ] Time constraints - Available time affects verification depth
Outputs Produced
Core verification report:
- Claims extracted - Specific factual assertions identified
- Categorisation - Each claim classified (factual/interpretive/opinion/uncheckable)
- Sources evaluated - Quality assessment using RADAR criteria for each source
- Verification findings - Evidence for/against each claim with source attribution
- Confidence assessment - Calibrated rating (confirmed/likely/possible/unverified/disputed)
- Audit trail - Complete documentation of verification process
Optional outputs:
- Recommendations for addressing unverified or disputed claims
- Flags for claims requiring domain expert review
- Suggested corrections for identified inaccuracies
Operating Principles
Medium freedom with preferred patterns:
- Follow the core workflow sequentially (claim categorisation → source mode → verification → confidence assignment)
- Apply SIFT method and triangulation protocols as standard practice
- Use RADAR criteria for source quality assessment (see
references/source-evaluation-radar.md) - Adapt verification depth based on claim significance and risk
- Exercise judgement on when to escalate to domain experts
Non-negotiable standards:
- Apply identical verification standards to all claims (non-partisanship)
- Document all sources consulted with transparent audit trail
- Use calibrated confidence language (never present uncertain claims as certain)
- Surface disagreements between authoritative sources rather than hiding them
- Prioritise primary sources over secondary sources over tertiary sources
Core Workflow
Phase 1: Claim Extraction and Categorisation
Step 1: Extract specific factual claims
Identify discrete, verifiable assertions within the content.
Questions to guide extraction:
- What specific statements are presented as facts?
- Which claims involve names, dates, numbers, statistics, or events?
- What causal relationships or predictions are asserted?
- Are there embedded factual claims within interpretive passages?
Example:
- Content: "The UK's ageing population, which reached 67.3 million in 2021, will strain healthcare resources."
- Extracted claims:
- Claim 1: "UK population reached 67.3 million in 2021" (factual)
- Claim 2: "UK population is ageing" (factual, requires definition)
- Claim 3: "Ageing population will strain healthcare resources" (interpretive/predictive)
Step 2: Categorise each claim
Use the three-category taxonomy to determine verification approach.
Category 1: Factual/Verifiable Claims
- Definition: Statements provable or disprovable using objective evidence
- Characteristics: Specific, testable, has objective truth value
- Examples: Statistics, dates, historical events, scientific findings
- Action: Proceed with full verification
Category 2: Interpretive/Analytical Claims
- Definition: Combines facts with interpretation, analysis, or prediction
- Characteristics: Requires reasoning assessment, involves judgement
- Examples: Causal claims, predictions, impact assessments
- Action: Verify factual basis, assess reasoning quality
Category 3: Opinion/Non-Verifiable Statements
- Definition: Values, beliefs, preferences, or personal experiences
- Characteristics: Subjective, no objective standard for verification
- Examples: Aesthetic judgements, moral prescriptions, preferences
- Action: Do not attempt to fact-check; flag as opinion
Step 3: Filter uncheckable claims
Identify claims that cannot be verified even if factual in nature.
Uncheckable categories:
- Predictions about the future - Cannot verify until time passes
- Personal experiences - No external verification possible
- Vague claims - "Many people believe..." (who? how many?)
- Hypotheticals - "If X had happened, Y would have occurred"
Action: Flag as uncheckable and note why verification is impossible.
Step 4: Prioritise verification efforts
For multiple claims, assess priority based on:
- Significance - Claims affecting key conclusions or decisions (highest priority)
- Specificity - Concrete, checkable assertions (easier to verify efficiently)
- Risk - High-stakes contexts require thorough verification
- Feasibility - Available sources and expertise
Focus resources on high-priority factual claims.
Phase 2: Source Mode Selection and Discovery
Choose verification approach based on context.
Mode A: Retrospective Verification (Sources Provided)
When to use: Checking claims against provided context, documents, or source material. Common for detecting extrinsic hallucinations in AI-generated content.
Protocol:
- Extract claims from AI output or document
- Compare systematically against provided sources
- Flag contradictions (claim conflicts with sources - severity high)
- Flag unsupported claims (claim unaddressed by sources when sources should cover it - severity medium)
- Verify supported claims (claim explicitly backed by provided sources - severity low/none)
Extrinsic hallucination checklist:
- [ ] Are statistics and numbers present in provided sources?
- [ ] Are quoted statements actually from cited sources?
- [ ] Are causal claims supported by provided research?
- [ ] Are dates, names, and specific details consistent with sources?
- [ ] Does output acknowledge limitations mentioned in sources?
- [ ] Are confidence levels calibrated to source certainty?
Key focus: Detecting when AI ignores or contradicts provided ground truth.
For detailed AI hallucination detection methods, see references/hallucination-detection.md.
Mode B: Proactive Validation (Find Sources)
When to use: No sources provided, or provided sources insufficient. Requires web search and source discovery.
Protocol - Apply SIFT Method:
S - Stop
- Pause before accepting or sharing claim
- Check your emotional reaction (strong emotions = increased checking needed)
- Assess claim plausibility (extraordinary claims require extraordinary evidence)
I - Investigate the Source
- Practice lateral reading: leave the source and open new tabs
- Search what trusted sources say about the original source
- Check fact-checking sites (Snopes, FactCheck.org, PolitiFact)
- Look for Wikipedia entries on organisations or publications
- Search "[source name] + bias" or "[source name] + credibility"
F - Find Better Coverage
- Search for other trusted sources on the same topic
- Look for consensus across multiple reputable sources
- Prioritise primary sources (original research, official data)
- Check if major news organisations (Reuters, AP, BBC) covered the story
- Seek peer-reviewed research for scientific claims
T - Trace Claims, Quotes, and Media
- Follow quotes back to original context
- Verify images haven't been taken out of context
- Check if statistics are cited correctly
- Look for original research papers or official documents
- Confirm claim-makers are quoted accurately
Phase 3: Source Quality Assessment
Evaluate every source using RADAR criteria.
Apply systematically to each source before weighting its evidence. For detailed RADAR framework with red flags and scoring guidance, see references/source-evaluation-radar.md.
Quick RADAR summary:
- R - Rationale (Purpose and Bias): Why was this created? Are important facts omitted? Is language neutral or emotionally charged?
- A - Authority (Credibility): What are the author's credentials? Is the author affiliated with reputable institutions?
- D - Date (Currency): When was this published? Is this information still current for the field?
- A - Accuracy (Verification): Does this cite reliable sources? Can you verify key claims elsewhere?
- R - Relevance (Applicability): Does this directly address your research question?
Priority: Always prefer official/primary sources over third-party interpretations.
Phase 4: Evidence Hierarchy and Weighting
Apply systematic source weighting using the primary/secondary/tertiary framework.
Tier 1: Primary Sources (Highest Weight)
Definition: Original documents of events, discoveries, or research.
Examples: Original research papers, official statistics (ONS, census), historical documents, legislation, patents, official organisational statements
Weight: 90-100% confidence when multiple primary sources agree
Standard: "Always prefer primary sources over secondary sources." When primary sources exist, cite them directly.
Tier 2: Secondary Sources (High Weight)
Definition: Analysis, reviews, or summaries of primary sources providing context and interpretation.
Examples: Literature reviews and meta-analyses, academic textbooks, reputable news reporting (Reuters, AP, BBC), systematic reviews, expert analysis citing primary evidence
Weight: 70-89% confidence when multiple quality secondary sources agree
Use cases: When primary sources are inaccessible or require expert interpretation.
Tier 3: Tertiary Sources (Low Weight)
Definition: Indexes or consolidations of primary and secondary sources without new analysis.
Examples: Encyclopaedias (including Wikipedia), dictionaries, handbooks, fact books and almanacs
Weight: Useful for orientation only; insufficient for citation
Standard: "Tertiary sources are usually not acceptable as cited sources in research because they are so far from firsthand information."
Appropriate use: Initial orientation, finding primary/secondary sources, quick fact checks requiring verification.
For context-dependent adjustments and detailed weighting guidance, see references/evidence-hierarchy.md.
Phase 5: Multi-Source Triangulation
Verify significant factual claims with at least three independent, high-quality sources.
Triangulation Protocol
Step 1: Ensure source independence
Verify sources are truly independent:
- Not citing each other directly
- Different organisations/institutions
- Different methodologies or data sources
- Different perspectives or contexts
Red flag: Three sources all citing the same original claim without independent verification provides weak triangulation.
Step 2: Apply data triangulation
Check claims across:
- Different time periods (temporal consistency)
- Different geographic locations (spatial consistency)
- Different groups or populations (demographic consistency)
Step 3: Seek consensus
Strong consensus (3+ high-quality sources agree):
- Confidence: Confirmed
- Action: Accept as established fact with attribution
Weak consensus (2 sources agree, 1 disagrees):
- Confidence: Likely
- Action: Investigate outlier, weight by source quality, note disagreement
No consensus (sources contradict):
- Confidence: Disputed
- Action: Proceed to conflicting source resolution protocol (Phase 6)
Step 4: Document triangulation
Record for audit trail:
- Which sources consulted
- Points of agreement and disagreement
- Quality assessment for each source
- Rationale for final confidence rating
Phase 6: Handling Conflicting Sources
Five-step resolution protocol:
1. Identify disagreement: Pinpoint exactly what sources disagree about (facts vs interpretation? same question? different contexts? Example: Different unemployment figures may reflect different dates or methodologies)
2. Analyse methodologies: Examine how each source arrived at their conclusion (methods used, assumptions, data access, limitations, could methodology explain discrepancy?)
3. Assess source quality: Apply RADAR to each. Weight by: primary vs secondary, expertise in domain, track record, recency (context-dependent), independence
4. Seek additional sources: Find third/fourth sources to break tie (search for primary sources, consult experts, check authoritative bodies, systematic reviews, fact-checking organisations). When multiple high-quality sources agree, outliers receive less weight.
5. Transparent attribution: Present disagreement with caveats. Core principle: "Surface the conflict rather than quietly averaging it away." Use patterns like "Source A argues X, while Source B maintains Y" or "Most experts agree X, though [Source Y] argues Z" or "Evidence insufficient; experts divided." Assign "Disputed" when authoritative sources disagree and resolution unclear.
Phase 7: Confidence Calibration and Documentation
Assign calibrated confidence levels and create transparent audit trail.
Confidence Level Definitions
Confirmed (90-100% confidence)
- Multiple high-quality independent sources agree
- Primary sources available and consistent
- No credible contradictory evidence
- Language: "Confirmed," "Established fact," "Verified"
Likely (70-89% confidence)
- Strong support from quality sources
- Majority of sources agree
- Minor uncertainties or gaps remain
- Language: "Likely," "Probably," "Strong evidence suggests"
Possible (50-69% confidence)
- Some credible support
- Limited independent verification
- Significant uncertainties remain
- Language: "Possible," "May be," "Some evidence suggests"
Unverified (30-49% confidence)
- Insufficient evidence to confirm
- Single-source claims without corroboration
- Unable to find authoritative sources
- Language: "Unverified," "Cannot confirm," "Insufficient evidence"
Disputed (varies)
- Authoritative sources explicitly disagree
- Methodological conflicts unresolved
- Expert opinion divided
- Language: "Disputed," "Experts disagree," "Conflicting evidence"
Note: Confidence percentages are indicative ranges based on source quality and triangulation strength, not calculated scores. Use the qualitative criteria (multiple sources agree, etc.) as primary guidance.
Documentation Requirements
Create complete audit trail: Claims extracted, categorisation rationale, sources consulted (with RADAR), search strategies, verification findings, triangulation results, conflict resolution, confidence assignment rationale, limitations acknowledged.
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Source & license
This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.
- Author: isvlasov
- Source: isvlasov/rageatc-oss
- License: MIT
Install and usage instructions live in the source repository linked above.
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Versions
- v0.1.0 Imported from the upstream source.