diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index 11446d222..e089e6d3d 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -671,21 +671,21 @@ func (al *AgentLoop) PublishResponseIfNeeded(ctx context.Context, channel, chatI
 		return
 	}
 
-	alreadySent := false
+	alreadySentToSameChat := false
 	defaultAgent := al.GetRegistry().GetDefaultAgent()
 	if defaultAgent != nil {
 		if tool, ok := defaultAgent.Tools.Get("message"); ok {
 			if mt, ok := tool.(*tools.MessageTool); ok {
-				alreadySent = mt.HasSentInRound()
+				alreadySentToSameChat = mt.HasSentTo(channel, chatID)
 			}
 		}
 	}
 
-	if alreadySent {
+	if alreadySentToSameChat {
 		logger.DebugCF(
 			"agent",
-			"Skipped outbound (message tool already sent)",
-			map[string]any{"channel": channel},
+			"Skipped outbound (message tool already sent to same chat)",
+			map[string]any{"channel": channel, "chat_id": chatID},
 		)
 		return
 	}
diff --git a/pkg/tools/message.go b/pkg/tools/message.go
index 064065a38..5a384b37e 100644
--- a/pkg/tools/message.go
+++ b/pkg/tools/message.go
@@ -3,14 +3,21 @@ package tools
 import (
 	"context"
 	"fmt"
-	"sync/atomic"
+	"sync"
 )
 
 type SendCallback func(channel, chatID, content, replyToMessageID string) error
 
+// sentTarget records the channel+chatID that the message tool sent to.
+type sentTarget struct {
+	Channel string
+	ChatID  string
+}
+
 type MessageTool struct {
 	sendCallback SendCallback
-	sentInRound  atomic.Bool // Tracks whether a message was sent in the current processing round
+	mu           sync.Mutex
+	sentTargets  []sentTarget // Tracks all targets sent to in the current round
 }
 
 func NewMessageTool() *MessageTool {
@@ -53,12 +60,30 @@ func (t *MessageTool) Parameters() map[string]any {
 // ResetSentInRound resets the per-round send tracker.
 // Called by the agent loop at the start of each inbound message processing round.
 func (t *MessageTool) ResetSentInRound() {
-	t.sentInRound.Store(false)
+	t.mu.Lock()
+	t.sentTargets = t.sentTargets[:0]
+	t.mu.Unlock()
 }
 
 // HasSentInRound returns true if the message tool sent a message during the current round.
 func (t *MessageTool) HasSentInRound() bool {
-	return t.sentInRound.Load()
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return len(t.sentTargets) > 0
+}
+
+// HasSentTo returns true if the message tool sent to the specific channel+chatID
+// during the current round. Used by PublishResponseIfNeeded to avoid suppressing
+// the final response when the message tool only sent to a different conversation.
+func (t *MessageTool) HasSentTo(channel, chatID string) bool {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	for _, st := range t.sentTargets {
+		if st.Channel == channel && st.ChatID == chatID {
+			return true
+		}
+	}
+	return false
 }
 
 func (t *MessageTool) SetSendCallback(callback SendCallback) {
@@ -98,7 +123,10 @@ func (t *MessageTool) Execute(ctx context.Context, args map[string]any) *ToolRes
 		}
 	}
 
-	t.sentInRound.Store(true)
+	t.mu.Lock()
+	t.sentTargets = append(t.sentTargets, sentTarget{Channel: channel, ChatID: chatID})
+	t.mu.Unlock()
+
 	// Silent: user already received the message directly
 	return &ToolResult{
 		ForLLM: fmt.Sprintf("Message sent to %s:%s", channel, chatID),