diff --git a/src/agents/embedded-agent-subscribe.handlers.messages.test-support.ts b/src/agents/embedded-agent-subscribe.handlers.messages.test-support.ts
index d6c104806f57..f7850b6d8bb7 100644
--- a/src/agents/embedded-agent-subscribe.handlers.messages.test-support.ts
+++ b/src/agents/embedded-agent-subscribe.handlers.messages.test-support.ts
@@ -39,10 +39,6 @@ type EmbeddedSubscribeMessagesTestApi = {
       visibleDelta: string;
     },
   ): { hold: boolean; text: string };
-  resolveSilentReplyFallbackText(params: {
-    text: unknown;
-    messagingToolSentTexts: string[];
-  }): string;
 };
 
 function getTestApi(): EmbeddedSubscribeMessagesTestApi {
@@ -79,10 +75,3 @@ export function resolveCurrentSourceMessagingToolPartial(
 ): { hold: boolean; text: string } {
   return getTestApi().resolveCurrentSourceMessagingToolPartial(state, params);
 }
-
-export function resolveSilentReplyFallbackText(params: {
-  text: unknown;
-  messagingToolSentTexts: string[];
-}): string {
-  return getTestApi().resolveSilentReplyFallbackText(params);
-}
diff --git a/src/agents/embedded-agent-subscribe.handlers.messages.test.ts b/src/agents/embedded-agent-subscribe.handlers.messages.test.ts
index bba3cf0ec884..25516f954a13 100644
--- a/src/agents/embedded-agent-subscribe.handlers.messages.test.ts
+++ b/src/agents/embedded-agent-subscribe.handlers.messages.test.ts
@@ -16,7 +16,6 @@ import {
   buildAssistantStreamData,
   recordPendingAssistantReplyDirectives,
   resolveCurrentSourceMessagingToolPartial,
-  resolveSilentReplyFallbackText,
 } from "./embedded-agent-subscribe.handlers.messages.test-support.js";
 import type { EmbeddedAgentSubscribeContext } from "./embedded-agent-subscribe.handlers.types.js";
 import {
@@ -237,50 +236,6 @@ function createMessageToolEnvelope(message: string, args: Record<string, unknown
   });
 }
 
-describe("resolveSilentReplyFallbackText", () => {
-  it("replaces NO_REPLY with latest messaging tool text when available", () => {
-    expect(
-      resolveSilentReplyFallbackText({
-        text: "NO_REPLY",
-        messagingToolSentTexts: ["first", "final delivered text"],
-      }),
-    ).toBe("final delivered text");
-  });
-
-  it("keeps original text when response is not NO_REPLY", () => {
-    expect(
-      resolveSilentReplyFallbackText({
-        text: "normal assistant reply",
-        messagingToolSentTexts: ["final delivered text"],
-      }),
-    ).toBe("normal assistant reply");
-  });
-
-  it("keeps NO_REPLY when there is no messaging tool text to mirror", () => {
-    expect(
-      resolveSilentReplyFallbackText({
-        text: "NO_REPLY",
-        messagingToolSentTexts: [],
-      }),
-    ).toBe("NO_REPLY");
-  });
-
-  it("tolerates malformed text payloads without throwing", () => {
-    expect(
-      resolveSilentReplyFallbackText({
-        text: undefined,
-        messagingToolSentTexts: ["final delivered text"],
-      }),
-    ).toBe("");
-    expect(
-      resolveSilentReplyFallbackText({
-        text: "NO_REPLY",
-        messagingToolSentTexts: [42 as unknown as string],
-      }),
-    ).toBe("42");
-  });
-});
-
 describe("hasAssistantVisibleReply", () => {
   it("treats audio-only payloads as visible", () => {
     expect(hasAssistantVisibleReply({ audioAsVoice: true })).toBe(true);
@@ -1705,6 +1660,71 @@ describe("handleMessageEnd", () => {
     },
   );
 
+  it("keeps exact NO_REPLY silent after a user-facing message send followed by sessions_send (#119383)", () => {
+    const emitBlockReply = vi.fn();
+    const finalizeAssistantTexts = vi.fn();
+    const ctx = createMessageEndContext({
+      emitBlockReply,
+      finalizeAssistantTexts,
+      consumeReplyDirectives: vi.fn((text: string) => ({ text })),
+      state: {
+        blockBuffer: "",
+        deltaBuffer: "",
+        messagingToolSentTexts: ["<user-facing reply>", "<internal escalation note>"],
+        messagingToolSentTextsNormalized: ["<user-facing reply>", "<internal escalation note>"],
+        messagingToolSentTargets: [
+          {
+            tool: "message",
+            provider: "whatsapp",
+            to: "user:123",
+            text: "<user-facing reply>",
+          },
+        ],
+      },
+    });
+
+    void endMessage(ctx, {
+      message: { role: "assistant", content: [{ type: "text", text: "NO_REPLY" }] },
+    });
+
+    // The exact silent token must never be rewritten to the sessions_send body:
+    // the final assistant text keeps NO_REPLY and no block reply carries the note.
+    expect(finalizeAssistantTexts).toHaveBeenCalledWith(
+      expect.objectContaining({ text: "NO_REPLY" }),
+    );
+    for (const call of emitBlockReply.mock.calls) {
+      expect(JSON.stringify(call)).not.toContain("<internal escalation note>");
+    }
+  });
+
+  it("keeps exact NO_REPLY silent when only sessions_send delivered (#119383)", () => {
+    const emitBlockReply = vi.fn();
+    const finalizeAssistantTexts = vi.fn();
+    const ctx = createMessageEndContext({
+      emitBlockReply,
+      finalizeAssistantTexts,
+      consumeReplyDirectives: vi.fn((text: string) => ({ text })),
+      state: {
+        blockBuffer: "",
+        deltaBuffer: "",
+        messagingToolSentTexts: ["<internal escalation note>"],
+        messagingToolSentTextsNormalized: ["<internal escalation note>"],
+        messagingToolSentTargets: [],
+      },
+    });
+
+    void endMessage(ctx, {
+      message: { role: "assistant", content: [{ type: "text", text: "NO_REPLY" }] },
+    });
+
+    expect(finalizeAssistantTexts).toHaveBeenCalledWith(
+      expect.objectContaining({ text: "NO_REPLY" }),
+    );
+    for (const call of emitBlockReply.mock.calls) {
+      expect(JSON.stringify(call)).not.toContain("<internal escalation note>");
+    }
+  });
+
   it.each([
     {
       name: "counts a completed provider assistant message",
diff --git a/src/agents/embedded-agent-subscribe.handlers.messages.ts b/src/agents/embedded-agent-subscribe.handlers.messages.ts
index faa5fa61f77d..453853e407d5 100644
--- a/src/agents/embedded-agent-subscribe.handlers.messages.ts
+++ b/src/agents/embedded-agent-subscribe.handlers.messages.ts
@@ -446,23 +446,6 @@ function copyPartialBlockState(
   target.pendingTagFragment = source.pendingTagFragment;
 }
 
-/** Replaces a silent-reply token with the latest sent messaging-tool text when available. */
-function resolveSilentReplyFallbackText(params: {
-  text: unknown;
-  messagingToolSentTexts: string[];
-}): string {
-  const text = coerceChatContentText(params.text);
-  const trimmed = text.trim();
-  if (trimmed !== SILENT_REPLY_TOKEN) {
-    return text;
-  }
-  const fallback = coerceChatContentText(params.messagingToolSentTexts.at(-1)).trim();
-  if (!fallback) {
-    return text;
-  }
-  return fallback;
-}
-
 function clearPendingToolMedia(
   state: Pick<
     EmbeddedAgentSubscribeState,
@@ -1257,7 +1240,6 @@ if (process.env.VITEST || process.env.NODE_ENV === "test") {
     buildAssistantStreamData,
     recordPendingAssistantReplyDirectives,
     resolveCurrentSourceMessagingToolPartial,
-    resolveSilentReplyFallbackText,
   };
 }
 
@@ -1357,10 +1339,10 @@ export function handleMessageEnd(
     ? ctx.stripBlockTags(visibleText, { thinking: false, final: false }, { final: true })
     : visibleText;
 
-  const text = resolveSilentReplyFallbackText({
-    text: finalVisibleText,
-    messagingToolSentTexts: ctx.state.messagingToolSentTexts,
-  });
+  // Exact NO_REPLY stays silent. The legacy rewrite (silentReplyRewrite) was
+  // removed by contract; global messaging-tool send evidence is not a
+  // user-route reply and must never be mirrored into the final payload.
+  const text = finalVisibleText;
   const rawThinking =
     ctx.state.includeReasoning || ctx.state.streamReasoning
       ? extractAssistantThinking(assistantMessage) || extractThinkingFromTaggedText(rawText)