factcheck-guard
Use this skill when making any factual claim about the codebase — existence, absence, or behavior. Converts the claim-verification rule into a systematic action protocol that prevents false assertions from grep-only results.
npx skills add vibeeval/vibecosystem --skill factcheck-guard --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# FactCheck Guard — Runtime Claim Verification Prevents false claims about the codebase. Grep results are hypotheses, not proof. Every assertion about "what the code does" must be verified by reading the actual code. ## Why This Exists An 80% false claim rate was observed when agents trusted grep results without reading files. The pattern repeats: grep finds a string, agent asserts behavior, behavior is wrong. This skill converts the claim-verification guidelines into an actionable protocol. ## Confidence Markers (MANDATORY) Every factual claim about the codebase MUST carry one of these markers: | Marker | Meaning | Requirements | |--------|---------|-------------| | [VERIFIED] | Read the file, traced the logic | Must cite file:line | | [INFERRED] | Based on grep or file name | Must verify before asserting to others | | [UNCERTAIN] | Not yet checked | Must investigate before making the claim | Never promote an [INFERRED] claim to a statement of fact. Never let [UNCERTAIN] appear in a response to the user — investigate first. --- ## Verification Protocol ### Level 1: Existence Claims When asserting "X exists in the codebase": **Step 1 — Search (produces [INFERRED])** ``` Grep/Glob f
- Why This Exists
- Confidence Markers (MANDATORY)
- Verification Protocol
- Level 1: Existence Claims
- Level 2: Absence Claims
- Level 3: Behavior Claims
- Common False Claim Patterns
- Two-Pass Audit Protocol
- Pass 1: Generate Hypotheses
- Pass 2: Verify Each Hypothesis
- Quick Checklist
- Integration Points
- Examples: Wrong vs Right
What does the factcheck-guard skill do?
Use this skill when making any factual claim about the codebase — existence, absence, or behavior. Converts the claim-verification rule into a systematic action protocol that prevents false assertions from grep-only results.
How do I install it?
Run `npx skills add vibeeval/vibecosystem --skill factcheck-guard --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From vibeeval/vibecosystem, a repository with 521 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.