diff --git a/.agent/rules/changelog.md b/.agent/rules/changelog.md
new file mode 100644
index 0000000000..ee0c1d0e7f
--- /dev/null
+++ b/.agent/rules/changelog.md
@@ -0,0 +1,7 @@
+---
+description: New changelog entries go in NEXT_CHANGELOG.md, not CHANGELOG.md
+globs:
+  - "CHANGELOG.md"
+---
+
+**RULE: Do not add new release entries to `CHANGELOG.md`.** New entries for the upcoming release go in `NEXT_CHANGELOG.md`. `CHANGELOG.md` is updated automatically by the release process.