| name | claim-verification |
| description | Fact-check a claim against sources and return a verdict with evidence and confidence — supported, refuted, partially-supported, or unverifiable. Use when asked to 'verify', 'fact-check', 'is this true', or before publishing a statistic or scientific claim. |
| version | 0.1.0 |
| domain | research |
| tags | ["fact-check","verification","evidence","sources"] |
Claim Verification
A claim + (optional) sources → a verdict with evidence and a calibrated
confidence.
Purpose
Before a claim ships in a post, brief, or video, it should be checked. This skill
takes a single claim, gathers or accepts sources, and returns a structured verdict
that separates what the evidence supports from what it doesn't — with honest
confidence, not false certainty.
When it fires
- Keyword triggers:
verify, fact-check, is this true, confirm,
source check, debunk
- File triggers:
claims.md, fact-check/**
- Command triggers:
/claim-verification
Inputs
| Input | Required | Notes |
|---|
claim | yes | The exact statement to check. |
sources | no | Provided URLs/quotes; else the skill gathers them. |
strictness | no | standard (default) or high (primary sources only). |
Workflow
- Restate the claim precisely — pin the testable assertion; flag ambiguity.
✅ Check: the claim is falsifiable as stated.
- Gather evidence — find/accept sources; prefer primary and authoritative.
- Weigh — does the evidence support, refute, or only partly cover the claim?
Note source quality and any conflict.
- Verdict + confidence — assign one of the four verdicts and a confidence
level with a one-line rationale.
- Cite — quote the decisive evidence with locations.
Output contract
{
"claim": "string — restated precisely",
"verdict": "supported | refuted | partially-supported | unverifiable",
"confidence": "low | medium | high",
"evidence": [{ "quote": "string", "source": "string" }],
"rationale": "string",
"caveats": ["string"]
}
Tools & MCP
- Tools:
WebSearch, WebFetch, Read.
- MCP dependencies: optional docs/library MCP for technical claims.
Quality bar
Example
Input: "The James Webb Space Telescope orbits the Earth." → verdict refuted
(it orbits the Sun–Earth L2 point), high confidence, with a cited NASA source.
Built on SIP — Starlight Intelligence Protocol
Substrate: starlightintelligence.org/protocol v1.1.0
Layers used: [file-contract, attestation, sovereignty]
Vertical: starlight-agent-skills · portable capability layer
