diff --git a/docs/reference/protocols/goal-vision-replan-contract-v0.md b/docs/reference/protocols/goal-vision-replan-contract-v0.md
index 624b7f1839..58bf526ed6 100644
--- a/docs/reference/protocols/goal-vision-replan-contract-v0.md
+++ b/docs/reference/protocols/goal-vision-replan-contract-v0.md
@@ -112,7 +112,9 @@ is its `schema_version`, not its enclosing field. The shared TypeScript authorin
 boundary rejects misplaced declared deltas before any write, including through
 CLI and Turn. It does not infer a protocol from ordinary metadata field names.
 Existing packets may omit the nested schema version; an explicitly supplied
-version must match. Historical read compaction remains unchanged.
+version must match. The look-back rides the existing `--agent-vision-json`
+boundary, so it stays explicit without adding more inline CLI flags or expanding
+the heartbeat prompt. Historical read compaction remains unchanged.
 
 ```json
 {
diff --git a/examples/blocker-push-runtime-smoke.py b/examples/blocker-push-runtime-smoke.py
index e8c297b295..f47e59b616 100644
--- a/examples/blocker-push-runtime-smoke.py
+++ b/examples/blocker-push-runtime-smoke.py
@@ -219,7 +219,10 @@ def main() -> int:
         assert "reuse the value on retries" in compact_prompt, prompt
         assert "guard; 2 stalls->replan" in compact_prompt, prompt
         assert "no-change=`surface_only`/no spend" in compact_prompt, prompt
-        assert "unchanged->`--vision-unchanged-reason`" in compact_prompt, prompt
+        # The shipped writeback sentence moved to the mixed-language form in the
+        # same change that updated examples/control_plane/heartbeat-prompt-smoke.py;
+        # this assertion keeps the blocker-runtime path pinned to the same text.
+        assert "unchanged→真实`--vision-unchanged-reason`" in compact_prompt, prompt
 
     print("blocker-push-runtime-smoke ok")
     return 0