diff --git a/plugin/skills/using-scribe/SKILL.md b/plugin/skills/using-scribe/SKILL.md
index bb498c3..140089c 100644
--- a/plugin/skills/using-scribe/SKILL.md
+++ b/plugin/skills/using-scribe/SKILL.md
@@ -125,6 +125,24 @@ Two constraints on *how* that's achieved:
    worth reading while almost nothing is on it, so a check added out of
    tidiness costs the whole surface, not just that note.
 
+   **The sharper form of the same test: is the thing this note describes yours
+   to change?** If yes it is a decision — editing your own software is how it
+   changes, and you will know you did it. Measured against a real corpus, every
+   note that earned a check was about somebody ELSE's software: a signing
+   service, a forge, a hub, an SDK, a model, a dependency set.
+
+   **Three that look like candidates and are not:**
+   - **Resume pointers and "current state" notes.** They go stale fastest of
+     anything, which is exactly why they tempt — but the cure is to update or
+     delete them, not to schedule a check. A sweep full of pointers is a sweep
+     nobody reads.
+   - **Measurements of your own system.** They go false because you changed
+     something, and you knew. A measurement earns a check only when what it
+     measures is outside your control.
+   - **A decision that RESTS on somebody else's behaviour.** The decision is
+     still a decision. Put the check on the note asserting the fact, and link
+     the decision to it.
+
    Not for tasks — a task's decay is its status, and a done issue records what
    happened rather than asserting something that can go false. Not for snippets
    either: `verify_snippet` compares the recorded location and code against the
diff --git a/src/scribe/mcp/tools/notes.py b/src/scribe/mcp/tools/notes.py
index 9b0aa9f..24843cc 100644
--- a/src/scribe/mcp/tools/notes.py
+++ b/src/scribe/mcp/tools/notes.py
@@ -147,7 +147,16 @@ async def create_note(
             and it goes false with nobody watching. Only constraints get a
             check.
             The test, in one question: COULD THIS NOTE BECOME FALSE WITHOUT
-            ANYONE EDITING IT? If no, leave this empty.
+            ANYONE EDITING IT? If no, leave this empty. Sharper still: is the
+            thing this note describes YOURS TO CHANGE? If yes it is a
+            decision. Measured against a real corpus, every note that earned a
+            check was about somebody else's software.
+            Three that look like candidates and are not: a resume pointer or
+            "current state" note (goes stale fastest, but the cure is to
+            update it, not to check it); a measurement of your own system (it
+            goes false because you changed something, and you knew); and a
+            decision that RESTS on someone else's behaviour (check the note
+            asserting the fact, not the decision).
             A command, a path, a URL, a query. Prose is allowed; something
             runnable is better.
         expires_when: The STATE that ends it — deliberately not a date.