diff --git a/.agents/skills/release-changelog-discord-message/SKILL.md b/.agents/skills/release-changelog-discord-message/SKILL.md
index 7852ad1a83..cd8cc50af3 100644
--- a/.agents/skills/release-changelog-discord-message/SKILL.md
+++ b/.agents/skills/release-changelog-discord-message/SKILL.md
@@ -163,6 +163,9 @@ Mimic this register; do not invent a "professional" tone.
 - **"WHATS NEXT" is forward-looking themes**, not a literal sprint list. 3–5
   bullets is the right size. Pull these from active goals, in-flight projects,
   and recent issues the team is working on — do not invent themes.
+- **Highlights follow the changelog skill's delta rule**: a feature the
+  previous announcement already introduced appears only for what changed
+  this release, and does not headline twice for follow-through work.
 - **"What's on my mind"** is dotta's personal/strategic thinking — docs gaps,
   philosophical positioning ("we're the human control plane for ai labor"),
   invitations ("if you've ever wanted to write about how you use Paperclip,
diff --git a/.agents/skills/release-changelog/SKILL.md b/.agents/skills/release-changelog/SKILL.md
index da1d141d33..55e7b360ea 100644
--- a/.agents/skills/release-changelog/SKILL.md
+++ b/.agents/skills/release-changelog/SKILL.md
@@ -168,6 +168,14 @@ Guidelines:
 - write from the user perspective
 - keep highlights short and concrete
 - spell out upgrade actions for breaking changes
+- **describe deltas, not repeats**: read the previous stable's notes
+  (`releases/v<last-stable>.md`) before writing. When they already
+  introduced a feature, this release's entry covers only what changed —
+  a default flip, a hardening, a completion — phrased against the prior
+  release ("last release introduced X; this release makes it the
+  default"), never re-describing the feature as if it debuted. A theme
+  that headlined the previous release does not headline again for
+  follow-through work; demote it to Improvements.
 
 ### Inline PR and contributor attribution