source-check git:20261010.3ba1fbeA

Immutable. This exact content never changes and is served at /api/v1/blob/eeea2a096e9e2998.

---
name: source-check
description: >-
  Use this after drafting an article, before publish, to verify every factual
  claim and statistic against a named source.
---
# Source check

Verify every factual claim before publish. Read-only except adding a Sources section.

## Pass 1 — Extract

Line by line, log factual claims, statistics, attributed statements, historical claims, causal assertions. Skip clearly labeled personal opinion.

## Pass 2 — Verify

For each claim, in order: named in the draft, then available files/notes, then a primary web source. Rate: Verified, Unverified, Unsupported, Overstated. Record publication, title, date, URL.

## Pass 3 — Quality

Flag single-source lean, stale stats, cherry-picking, vague attribution (“studies show”, “experts agree”), weak outlets.

## Pass 4 — Sources section

Numbered list grouped by section. Update, do not duplicate.

## Verdict

Solid / Mostly solid / Needs work / Unreliable. Suggest a fix for every problem. Do not rewrite prose.

Original sources only. If a reporter cites a study, cite the study. Personal observation and common knowledge do not need a citation.

Source: adapted from [Nadiem Mahmoud, source-check](https://github.com/nadiem99/claude-writing-skills/blob/5b52111e1bd30e93643929f17155e82aa26f771f/skills/pipeline/source-check/SKILL.md). MIT; see [third-party notices](../../../THIRD_PARTY_NOTICES.md).