fix(message): preserve same-round dedup by resetting only once per round

pkg/agent/loop.go

@@ -879,6 +879,9 @@ func (al *AgentLoop) runLLMIteration(
 func (al *AgentLoop) updateToolContexts(agent *AgentInstance, channel, chatID string) {
 	// Use ContextualTool interface instead of type assertions
 	if tool, ok := agent.Tools.Get("message"); ok {
+		if rt, ok := tool.(interface{ BeginRound() }); ok {
+			rt.BeginRound()
+		}
 		if mt, ok := tool.(tools.ContextualTool); ok {
 			mt.SetContext(channel, chatID)
 		}

pkg/tools/message.go

@@ -53,7 +53,12 @@ func (t *MessageTool) Parameters() map[string]any {
 func (t *MessageTool) SetContext(channel, chatID string) {
 	t.defaultChannel = channel
 	t.defaultChatID = chatID
-	t.sentInRound = false // Reset send tracking for new processing round
+}
+
+// BeginRound resets per-round send tracking.
+// AgentLoop calls this once per inbound message before tool iterations begin.
+func (t *MessageTool) BeginRound() {
+	t.sentInRound = false
 	t.lastChannel = ""
 	t.lastChatID = ""
 	t.lastContent = ""

pkg/tools/message_test.go

@@ -226,6 +226,36 @@ func TestMessageTool_Execute_SuppressDuplicateInSameRound(t *testing.T) {
 	}
 }
 
+func TestMessageTool_Execute_AllowsSameContentAfterBeginRound(t *testing.T) {
+	tool := NewMessageTool()
+	tool.SetContext("test-channel", "test-chat-id")
+
+	callCount := 0
+	tool.SetSendCallback(func(channel, chatID, content string) error {
+		callCount++
+		return nil
+	})
+
+	ctx := context.Background()
+	args := map[string]any{"content": "same message"}
+
+	first := tool.Execute(ctx, args)
+	if first.IsError || !first.Silent {
+		t.Fatalf("first result unexpected: %+v", first)
+	}
+
+	tool.BeginRound()
+	tool.SetContext("test-channel", "test-chat-id")
+
+	second := tool.Execute(ctx, args)
+	if second.IsError || !second.Silent {
+		t.Fatalf("second result unexpected: %+v", second)
+	}
+	if callCount != 2 {
+		t.Fatalf("send callback call count = %d, want 2", callCount)
+	}
+}
+
 func TestMessageTool_Name(t *testing.T) {
 	tool := NewMessageTool()
 	if tool.Name() != "message" {