diff --git a/_check.py b/_check.py
new file mode 100644
index 0000000..cb9e443
--- /dev/null
+++ b/_check.py
@@ -0,0 +1,12 @@
+import re
+missing = []
+for fname in ['src/main.rs','src/tui.rs','src/gvas.rs','src/ops.rs','src/discovery.rs','src/guard.rs','src/config.rs']:
+    lines = open(fname).readlines()
+    for i, line in enumerate(lines):
+        if re.match(r'^\s*fn\s+\w+', line):
+            prev = lines[i-1].strip() if i > 0 else ''
+            if not prev.startswith('///') and not prev.startswith('//'):
+                name = line.strip().split('(')[0].replace('fn ','')
+                missing.append((fname, i+1, name))
+for f,l,n in missing:
+    print(f'{f}:{l}: {n}')
diff --git a/skills/diligence/SKILL.md b/skills/diligence/SKILL.md
new file mode 100644
index 0000000..347aab9
--- /dev/null
+++ b/skills/diligence/SKILL.md
@@ -0,0 +1,16 @@
+---
+name: diligence
+description: Verification checklist for code changes — always run before claiming a task is complete.
+---
+
+# Diligence
+
+Before reporting any task as complete, verify:
+
+1. **Doc coverage** — run `python3 _check.py` to confirm zero undocumented functions.
+2. **Compilation** — `cargo check --workspace` must pass with no errors.
+3. **Git status** — no uncommitted changes unless intentionally deferred.
+4. **Remote parity** — `git log --oneline -1` matches `origin/master`.
+5. **Claim specificity** — report exactly what was done and what was verified, not what was assumed.
+
+Do not skip the check script. Do not assume prior passes still hold.