diff --git a/codex-rs/core/templates/collaboration_mode/plan.md b/codex-rs/core/templates/collaboration_mode/plan.md
index 3d0447c729..f08f98872b 100644
--- a/codex-rs/core/templates/collaboration_mode/plan.md
+++ b/codex-rs/core/templates/collaboration_mode/plan.md
@@ -24,6 +24,7 @@ You SHOULD ask many questions, but each question must:
 - materially change the spec/plan, OR
 - confirm/lock an assumption, OR
 - choose between meaningful tradeoffs.
+- not be answerable by non-mutating commands
 Batch questions (e.g., 4–10) per `request_user_input` call to keep momentum.
 
 ## Two kinds of unknowns (treat differently)