refactor: enhance event consumption logic and add graph tool completion test

internal/ai/runtime/executor/event_consumer.go

@@ -74,6 +74,8 @@ func consumeAgentEvents(events *adk.AsyncIterator[*adk.AgentEvent], summary *Run
 			summary.Status = "interrupted"
 		case strings.TrimSpace(summary.ReplyText) != "":
 			summary.Status = "completed"
+		case hasInvokedGraphTool(summary.InvokedToolCodes):
+			summary.Status = "completed"
 		default:
 			summary.Status = "fallback"
 		}
@@ -81,6 +83,15 @@ func consumeAgentEvents(events *adk.AsyncIterator[*adk.AgentEvent], summary *Run
 	summary.ToolCallCount = len(summary.InvokedToolCodes)
 }
 
+func hasInvokedGraphTool(toolCodes []string) bool {
+	for _, toolCode := range toolCodes {
+		if toolx.ResolveToolSourceType(toolCode) == enums.ToolSourceTypeGraph {
+			return true
+		}
+	}
+	return false
+}
+
 func buildInterruptSummaries(event *adk.AgentEvent) []InterruptContextSummary {
 	if event == nil || event.Action == nil || event.Action.Interrupted == nil {
 		return nil

internal/ai/runtime/executor/event_consumer_test.go

@@ -39,3 +39,34 @@ func TestConsumeAgentEventsUsesGraphToolTextAsReplyFallback(t *testing.T) {
 		t.Fatalf("unexpected summary status: %q", summary.Status)
 	}
 }
+
+func TestConsumeAgentEventsCompletesGraphToolWithNoVisibleReply(t *testing.T) {
+	summary := &RunResult{
+		Status:           "started",
+		InvokedToolCodes: make([]string, 0),
+	}
+	events, gen := adk.NewAsyncIteratorPair[*adk.AgentEvent]()
+	gen.Send(&adk.AgentEvent{
+		Output: &adk.AgentOutput{
+			MessageOutput: &adk.MessageVariant{
+				Role:     schema.Tool,
+				ToolName: toolx.GraphHandoffConversation.Name,
+				Message: &schema.Message{
+					Content: "",
+				},
+			},
+		},
+	})
+	gen.Close()
+
+	consumeAgentEvents(events, summary, nil, map[string]string{
+		toolx.GraphHandoffConversation.Name: toolx.GraphHandoffConversation.Code,
+	})
+
+	if summary.ReplyText != "" {
+		t.Fatalf("expected no reply text, got %q", summary.ReplyText)
+	}
+	if summary.Status != "completed" {
+		t.Fatalf("unexpected summary status: %q", summary.Status)
+	}
+}