fact-check-before-trust

verification-before-completion checks that a task was done. This skill checks that the facts are correct. An agent confidently reporting a £716 visa fee as £70,000 will pass completion verification — this skill catches it.

When to invoke

Invoke this skill before treating any agent output as authoritative when the output contains:

Numbers or money (prices, quantities, measurements, statistics)
Dates and deadlines (filing deadlines, release dates, expiry dates)
Named entities (people, organisations, laws, product names)
Causal claims ("X causes Y", "because of Z")
Superlatives ("the largest", "the only", "the most recent")

Skip for: code output, file system operations, and clearly self-contained tasks (renaming a variable, formatting a document).

Verification protocol

Step 1 — Extract claims Identify every verifiable claim in the output. List them explicitly:

Claim 1: UK visa fee is £716
Claim 2: Processing time is 3 weeks
Claim 3: Applies to Tier 2 (Skilled Worker) visa category

Step 2 — Score each claim For each claim, assign a confidence level:

High — Agent has direct evidence in its context (read a document, fetched a URL)
Medium — Agent inferred from training data (check recency)
Low — Agent stated without citing a source

Step 3 — Verify low/medium claims For each Low or Medium claim:

Search or re-fetch the source if possible
If source found: update confidence to High or mark Contradicted
If no source available: mark Unverifiable

Step 4 — Classify output

Result	Meaning
✓ Verified	All claims High confidence
⚠ Uncertain	1+ Unverifiable claims
✗ Contradicted	1+ claims conflict with found evidence

Step 5 — Surface to user

Verified: proceed
Uncertain: surface unverifiable claims with a note
Contradicted: stop, show the contradiction, do not use the output until resolved

Difference from verification-before-completion

verification-before-completion checks: "Did the agent do the task?" (task completion) fact-check-before-trust checks: "Is what the agent said true?" (output accuracy)

Both should be used for research, financial, legal, and compliance workflows.