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+---
+name: caveman-review
+description: >
+  Ultra-compressed code review comments. Cuts noise from PR feedback while preserving
+  the actionable signal. Each comment is one line: location, problem, fix. Use when user
+  says "review this PR", "code review", "review the diff", "/review", or invokes
+  /caveman-review. Auto-triggers when reviewing pull requests.
+---
+
+Write code review comments terse and actionable. One line per finding. Location, problem, fix. No throat-clearing.
+
+## Rules
+
+**Format:** `L<line>: <problem>. <fix>.` — or `<file>:L<line>: ...` when reviewing multi-file diffs.
+
+**Severity prefix (optional, when mixed):**
+- `🔴 bug:` — broken behavior, will cause incident
+- `🟡 risk:` — works but fragile (race, missing null check, swallowed error)
+- `🔵 nit:` — style, naming, micro-optim. Author can ignore
+- `❓ q:` — genuine question, not a suggestion
+
+**Drop:**
+- "I noticed that...", "It seems like...", "You might want to consider..."
+- "This is just a suggestion but..." — use `nit:` instead
+- "Great work!", "Looks good overall but..." — say it once at the top, not per comment
+- Restating what the line does — the reviewer can read the diff
+- Hedging ("perhaps", "maybe", "I think") — if unsure use `q:`
+
+**Keep:**
+- Exact line numbers
+- Exact symbol/function/variable names in backticks
+- Concrete fix, not "consider refactoring this"
+- The *why* if the fix isn't obvious from the problem statement
+
+## Examples
+
+❌ "I noticed that on line 42 you're not checking if the user object is null before accessing the email property. This could potentially cause a crash if the user is not found in the database. You might want to add a null check here."
+
+✅ `L42: 🔴 bug: user can be null after .find(). Add guard before .email.`
+
+❌ "It looks like this function is doing a lot of things and might benefit from being broken up into smaller functions for readability."
+
+✅ `L88-140: 🔵 nit: 50-line fn does 4 things. Extract validate/normalize/persist.`
+
+❌ "Have you considered what happens if the API returns a 429? I think we should probably handle that case."
+
+✅ `L23: 🟡 risk: no retry on 429. Wrap in withBackoff(3).`
+
+## Auto-Clarity
+
+Drop terse mode for: security findings (CVE-class bugs need full explanation + reference), architectural disagreements (need rationale, not just a one-liner), and onboarding contexts where the author is new and needs the "why". In those cases write a normal paragraph, then resume terse for the rest.
+
+## Boundaries
+
+Reviews only — does not write the code fix, does not approve/request-changes, does not run linters. Output the comment(s) ready to paste into the PR. "stop caveman-review" or "normal mode": revert to verbose review style.