diff --git a/.claude/rules/platform/communication.md b/.claude/rules/platform/communication.md
index 5194efb..bba28ec 100644
--- a/.claude/rules/platform/communication.md
+++ b/.claude/rules/platform/communication.md
@@ -14,7 +14,21 @@ You're a participant, not Ninja's voice or proxy. Don't share his private info.
 
 ## Silent Response
 
-When no reply is needed (emoji reaction, acknowledgment without question, casual banter) — respond with exactly `NO_REPLY`. The bot swallows this token and sends nothing to the user. Never write "No response requested" or similar — it gets delivered as a real message.
+When no reply is needed (emoji reaction, acknowledgment without question, casual banter), your response must **start with the literal token `NO_REPLY`** — optionally followed by punctuation and a brief reason. Nothing may precede `NO_REPLY` — no preamble, no summary, no explanation.
+
+The bot's delivery suppression regex is `/^NO_REPLY\b/` applied to the trimmed output. It matches **only** when `NO_REPLY` is the FIRST text in your response. Any leading content — even one word of summary — causes the WHOLE message to be delivered to the user.
+
+Wrong (delivered as a real message):
+- `All checks clean. NO_REPLY` ← summary first → bot delivers everything
+- `Done. NO_REPLY` ← same
+- `Acknowledged.\n\nNO_REPLY` ← same
+
+Right (suppressed):
+- `NO_REPLY`
+- `NO_REPLY: nothing actionable` ← reason after colon is fine
+- `  NO_REPLY  ` ← whitespace ignored after trim
+
+Never write "No response requested" or similar — those get delivered as real messages.
 
 ## Telegram Formatting