diff --git a/CLAUDE.md b/CLAUDE.md
index 81005a4..b995d75 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -7,6 +7,14 @@
 > wiki ([Use Cases](https://git.ltms.dev/fleet/fleetd/wiki/7-Use-Cases) → *The portable
 > CLAUDE.md block*); improvements go to the template first, then out to each project. Anything
 > specific to *this* repo lives under §Project addendum below, never inline above it.
+>
+> **Anything you measure in an addendum is perishable.** Date it, give the command that
+> re-measures it and what each outcome means, and tell the reader to delete the section once
+> it stops reproducing. The four parts work together: deciding what would falsify a claim is
+> the expensive step, and a reader in the middle of another task will not pay it, so a bare
+> "verify before relying on this" costs the same space and does nothing. The case this is for
+> is a note that goes stale as a live restriction — it will tell a future session it cannot do
+> the thing at the moment doing it becomes the job.
 
 If no `fleet_*` MCP tools are mounted in this session, this section does not apply — skip it.