diff --git a/prompts/claude-platform.md b/prompts/claude-platform.md
index cc819db..e52ff54 100644
--- a/prompts/claude-platform.md
+++ b/prompts/claude-platform.md
@@ -5,6 +5,18 @@ Use it to acknowledge a request before starting longer work.
 
 When working as a sub-agent or teammate, only use `send_message` if the main agent explicitly asked you to.
 
+## Background work never notifies you — finish within the turn
+
+Nothing in this environment re-invokes you when a background process, a background shell command, or a `run_in_background` job finishes. You will NOT be automatically notified when a build, compile, download, deploy, or any background task completes. The built-in tool descriptions that say "you'll be notified when it finishes" do NOT apply here.
+
+If you end your turn with a sentence like "I'll wait for the build to complete — I'll be notified", the turn simply ends and nothing ever resumes — the user is left stuck staring at that message. This is a real, repeated failure. Do not do it.
+
+Therefore:
+
+- Do not launch long work in the background and then end the turn expecting a callback. Run it in the foreground and block/poll until it actually finishes inside this same turn, then report the real result.
+- If something genuinely cannot complete within one turn, do not pretend a notification is coming. Finish with a concrete status and explicitly ask the user to send a follow-up message to continue. For recurring polling of CI/scheduled work, use the `schedule_task` / `watch_ci` tools, which DO re-invoke you.
+- Never leave an intermediate "I'll wait … I'll be notified" planning sentence as your final answer.
+
 ## Media attachments
 
 When a locally generated image, screenshot, video, audio, or document should appear in Discord, include a `MEDIA:` directive on its own line with an absolute local path:
diff --git a/src/message-runtime.test.ts b/src/message-runtime.test.ts
index 1cb64e3..deb15c8 100644
--- a/src/message-runtime.test.ts
+++ b/src/message-runtime.test.ts
@@ -4172,7 +4172,7 @@ describe('createMessageRuntime', () => {
       // First progress flushed when the second progress arrives
       expect(channel.sendAndTrack).toHaveBeenCalledWith(
         chatJid,
-        P('CI 상태 확인 중입니다.\n\n0초'),
+        P('CI 상태 확인 중입니다.'),
       );
       // Timer tick edits the tracked progress with updated elapsed time
       expect(channel.editMessage).toHaveBeenCalledWith(
@@ -4272,11 +4272,11 @@ describe('createMessageRuntime', () => {
     // First progress flushed when second arrives — sendAndTrack throws, falls back to sendMessage
     expect(channel.sendAndTrack).toHaveBeenCalledWith(
       chatJid,
-      P('진행 중입니다.\n\n0초'),
+      P('진행 중입니다.'),
     );
     expect(channel.sendMessage).toHaveBeenCalledWith(
       chatJid,
-      P('진행 중입니다.\n\n0초'),
+      P('진행 중입니다.'),
     );
   });
 
@@ -4353,11 +4353,11 @@ describe('createMessageRuntime', () => {
     // First progress flushed when second arrives — sendAndTrack returns null, falls back to sendMessage
     expect(channel.sendAndTrack).toHaveBeenCalledWith(
       chatJid,
-      P('진행 중입니다.\n\n0초'),
+      P('진행 중입니다.'),
     );
     expect(channel.sendMessage).toHaveBeenCalledWith(
       chatJid,
-      P('진행 중입니다.\n\n0초'),
+      P('진행 중입니다.'),
     );
   });
 
@@ -4461,7 +4461,7 @@ describe('createMessageRuntime', () => {
       expect(channel.sendAndTrack).toHaveBeenCalledTimes(1);
       expect(channel.sendAndTrack).toHaveBeenCalledWith(
         chatJid,
-        P('첫 번째 진행상황입니다.\n\n0초'),
+        P('첫 번째 진행상황입니다.'),
       );
       // Timer tick updates tracked progress via edit
       expect(channel.editMessage).toHaveBeenCalledWith(
@@ -4573,7 +4573,7 @@ describe('createMessageRuntime', () => {
       // First progress flushed when second arrives
       expect(channel.sendAndTrack).toHaveBeenCalledWith(
         chatJid,
-        P('오래 걸리는 작업입니다.\n\n0초'),
+        P('오래 걸리는 작업입니다.'),
       );
       // Timer ticks update the tracked progress with longer durations
       expect(channel.editMessage).toHaveBeenCalledWith(
@@ -4679,7 +4679,7 @@ describe('createMessageRuntime', () => {
       // First progress flushed when second arrives
       expect(channel.sendAndTrack).toHaveBeenCalledWith(
         chatJid,
-        P('테스트를 돌리는 중입니다.\n\n0초'),
+        P('테스트를 돌리는 중입니다.'),
       );
       // Timer tick updates tracked progress
       expect(channel.editMessage).toHaveBeenCalledWith(
@@ -5088,13 +5088,13 @@ describe('createMessageRuntime', () => {
       expect(channel.sendAndTrack).toHaveBeenNthCalledWith(
         1,
         chatJid,
-        P('첫 번째 진행상황입니다.\n\n0초'),
+        P('첫 번째 진행상황입니다.'),
       );
       // After empty final resets state, third progress flushed when fourth arrives (new message)
       expect(channel.sendAndTrack).toHaveBeenNthCalledWith(
         2,
         chatJid,
-        P('두 번째 진행상황입니다.\n\n0초'),
+        P('두 번째 진행상황입니다.'),
       );
       // Timer tick edits the first tracked progress
       expect(channel.editMessage).toHaveBeenCalledWith(
@@ -5213,7 +5213,7 @@ describe('createMessageRuntime', () => {
       // First progress flushed when second arrives
       expect(channel.sendAndTrack).toHaveBeenCalledWith(
         chatJid,
-        P('검증 중입니다.\n\n0초'),
+        P('검증 중입니다.'),
       );
       // Once the tracked progress exists, later progress updates replace the visible heading directly.
       expect(channel.editMessage).toHaveBeenCalledWith(
@@ -5329,7 +5329,7 @@ describe('createMessageRuntime', () => {
       // The first flushed progress is still tracked
       expect(channel.sendAndTrack).toHaveBeenCalledWith(
         chatJid,
-        P('진행 중입니다.\n\n0초'),
+        P('진행 중입니다.'),
       );
       // Edit is attempted on the tracked message (first fails, subsequent succeed)
       expect(channel.editMessage).toHaveBeenCalledWith(
@@ -5568,7 +5568,7 @@ describe('createMessageRuntime', () => {
     // First progress flushed when second arrives
     expect(channel.sendAndTrack).toHaveBeenCalledWith(
       chatJid,
-      P('중간 진행상황입니다.\n\n0초'),
+      P('중간 진행상황입니다.'),
     );
     // Error replaces the tracked progress message with the failure final
     expect(channel.sendMessage).not.toHaveBeenCalled();
diff --git a/src/message-turn-controller.ts b/src/message-turn-controller.ts
index 71f8fbe..6fb9f27 100644
--- a/src/message-turn-controller.ts
+++ b/src/message-turn-controller.ts
@@ -496,7 +496,10 @@ export class MessageTurnController {
         ? 0
         : Math.floor((Date.now() - this.progressStartedAt) / 5_000) * 5000;
 
-    const suffix = `\n\n${formatElapsedKorean(elapsedMs)}`;
+    // Skip the elapsed-time label until at least one 5s bucket has elapsed, so
+    // a freshly-created progress message doesn't show a meaningless "0초".
+    const suffix =
+      elapsedMs >= 5000 ? `\n\n${formatElapsedKorean(elapsedMs)}` : '';
     const body = this.composeProgressBody(text);
 
     this.persistProgressBody(body);