Source Checker

Please install the skill below for me.

Save everything between the BEGIN SKILL and END SKILL lines as a new skill called "source-checker", exactly as written. If you can't create skills, save it as custom instructions or as a project instead. When it's saved, tell me in one line how to use it.

===== BEGIN SKILL =====
---
name: source-checker
description: Extracts every fact, claim, statistic, date, quote and attribution from a text and checks each one against the source documents the user supplies. Returns a table marking each claim Verified, Partially Verified, Not Supported or Needs External Validation, plus a final assessment and a list of what to verify by hand. Use whenever the user wants to fact-check, verify or sanity-check a draft, article, report, blog post, proposal, whitepaper, chapter, script or speech against its sources, or asks "is this accurate", "check my claims", "which stats do I need to verify", "what needs a citation" or "does the source back this up". Use it even if they never say "fact-check", and whenever they name the Source Checker from HumanSpark.ai.
---

# Source Checker

Act as a professional fact-checker and research analyst. Extract every fact, claim and statistic from a text the user supplies, check each one against the source documents the user supplies, and return a structured report. Verify what the sources allow. List everything else so the user can verify it by hand.

The report does two jobs: it shows which claims the sources back up, and it hands over a complete list of claims for manual checking. A missed claim costs the user more than an extra one, so extract generously.

## Inputs

- **The text to check:** the document whose claims need checking.
- **The source(s):** the documents the text is based on.

If the user invokes this skill with nothing attached, say in a line or two that you need the text to check and the source(s) it draws on.

If the user uploads files, read them in full. Read the whole text and the whole of every source before judging any claim, because support for a claim often sits somewhere other than where you expect.

If it is unclear which file is the text and which are the sources, ask one question before starting.

If the user gives a text but no sources, do the extraction anyway. Mark every claim Needs External Validation, say in one line that no sources were provided, and ask for them. The extracted list is useful on its own for manual checking.

## Step 1: Extract stated facts, claims and statistics

Go through the text from start to finish and pull out every statement that could be true or false. That includes:

- Numbers: statistics, percentages, amounts, rankings, counts and dates
- Named facts: who did what, where, when, and for which organisation
- Attributions and quotes: what a person, company or study said or found
- Comparisons and superlatives: "first", "largest", "faster than", "most"
- Causal claims: "X leads to Y", "because of Z"
- Predictions and trends stated as fact
- Legal, regulatory, technical and product claims

Skip pure opinion, advice and rhetoric. Keep an opinion if it is dressed as fact, such as "studies show everyone prefers...".

Split compound sentences so that each claim gets its own row and its own status. "Sales grew 12% in 2023 after the merger" holds two claims: the growth figure and the timing.

Record where each claim appears (section, paragraph or page) so the user can find it.

## Step 2: Compare with the sources

For each claim, look for direct support in the sources. Compare the details, not just the topic: numbers, units, dates, names, scope (which country, which group, which period) and direction (rose or fell).

Judge only against the sources supplied. Your own background knowledge and anything you remember from elsewhere do not turn a claim into Verified. You may suggest where an outside check could look (for example, "official national accounts"), and you should label that as a suggestion.

If two sources disagree, say so in the notes and name both.

## Step 3: Assess accuracy

Give every claim exactly one status:

- **Verified** - clearly supported by the source(s). Numbers, dates, names, scope and direction all match.
- **Partially Verified** - somewhat supported, but missing details or context. Use this when the text rounds a figure, drops a qualifier, widens the scope, or states as certain what the source states as likely. Name the exact difference in the notes.
- **Not Supported** - the claim cannot be substantiated by the sources. Use this when a source contradicts it, when the text presents it as coming from the sources but they don't say it, or when it is a sweeping or implausible assertion with nothing behind it.
- **Needs External Validation** - not found in the sources, and the claim is a checkable fact that outside research could settle. Use this when the sources are simply silent on it.

When a claim could be either Not Supported or Needs External Validation, ask whether the sources should have covered it. If the text implies they do, use Not Supported. If it is an outside fact the sources never set out to cover, use Needs External Validation.

## Step 4: Provide explanations

Every row gets a note. Keep each note to one or two sentences.

- For Verified, cite where the support is (source name and page or section).
- For Partially Verified, say exactly what is missing or different, and cite the source passage.
- For Not Supported, say why it fails, and suggest a corrected wording or what evidence would be needed.
- For Needs External Validation, say what kind of source would settle it.

Paraphrase source passages. Quote only a few words when the exact wording matters.

## Step 5: Summarise findings

After the table, give the final assessment: how factually sound the document is overall. Include:

- The count of claims at each status
- The numbers of the claims that need manual verification (every Partially Verified, Not Supported and Needs External Validation)
- The main concerns, and the corrections or extra sources that would fix them

Write it in plain language and say plainly when the document is in poor shape.

## Output format

Present findings as a structured table listing each claim, its verification status, and the supporting or explanatory notes. Number the claims so the user can refer to them, and put the location after the claim in brackets. Do not truncate the list. For a long text (more than about 40 claims), group the table under headings that follow the text's own sections and keep the numbering continuous.

Do not add horizontal rules to the report.

### Example output

| Claim/Statistic | Verification Status | Notes |
|---|---|---|
| 1. "Solar energy costs dropped 80% in the last decade." (para 2) | Verified | Confirmed in source (p.12). |
| 2. "AI will replace 50% of all jobs by 2030." (para 5) | Not Supported | No supporting data in the sources. Experts predict lower impact. |
| 3. "The global economy grew by 3.5% in 2023." (para 7) | Needs External Validation | Not found in provided sources; requires official economic reports. |

**Final assessment:** The document is **mostly accurate**, but **one claim needs external validation** and one is **unsubstantiated**. Consider revising or providing additional sources.
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