double-check

name	double-check
description	Multi-model fact-checking. Opus checks independently, spawns a Sonnet sub-agent for a blind second review, then compares and reconciles both results into a consensus report.

Double-Check (Multi-Model Verification)

Perform independent fact-checks of a document using multiple Claude models, then reconcile results.

Procedure

Step 1: Identify the target

• Determine the target document from conversation context
• If ambiguous, ask the user to clarify

Step 2: Opus check (self)

• Read the target document thoroughly and fact-check for:
  • Technical accuracy (versions, APIs, config values, limits)
  • Numerical consistency (calculations, totals)
  • Internal contradictions (mismatches between sections)
  • Code example correctness
• Use WebSearch to verify against primary sources and cite evidence
• Classify each finding as: Correct / Needs Fix / Improvement Suggested

Step 3: Sonnet sub-agent independent check

• Launch a Sonnet sub-agent via the Task tool (model: "sonnet")
• Pass only the document path — do NOT share Opus findings (to ensure independence)
• Prompt:

Fact-check the following document.
Verify technical accuracy, numerical consistency, internal contradictions, and code example correctness.
Classify each finding as "Correct / Needs Fix / Improvement Suggested" with cited evidence.
Use WebSearch to verify against primary sources.

Target: <file path>

Step 4: Compare and reconcile

• Cross-reference both sets of findings
• Agreed findings → adopt directly
• Found by only one reviewer → Opus performs additional verification
• Conflicting opinions → resolve with additional WebSearch, decide based on evidence

Step 5: Consensus report

• Present the final report:

## Double-Check Results

**Target**: <document name>
**Reviewers**: Claude Opus 4.6 + Claude Sonnet 4.5

### Needs Fix
| # | Section | Issue | Evidence |
|---|---------|-------|----------|

### Improvement Suggested
| # | Section | Issue | Evidence |
|---|---------|-------|----------|

### Verified (Correct)
<list of key verified items>