diff --git a/internal/handler/agent.go b/internal/handler/agent.go
index b799d912..b3599c3f 100644
--- a/internal/handler/agent.go
+++ b/internal/handler/agent.go
@@ -725,7 +725,9 @@ func (h *AgentHandler) ProcessMessageForRobot(ctx context.Context, conversationI
 			"deep",
 		)
 		if errMA != nil {
-			h.persistEinoAgentTraceForResume(conversationID, resultMA)
+			if shouldPersistEinoAgentTraceAfterRunError(ctx) {
+				h.persistEinoAgentTraceForResume(conversationID, resultMA)
+			}
 			errMsg := "执行失败: " + errMA.Error()
 			if assistantMessageID != "" {
 				_, _ = h.db.Exec("UPDATE messages SET content = ?, updated_at = ? WHERE id = ?", errMsg, time.Now(), assistantMessageID)
@@ -2576,7 +2578,7 @@ func (h *AgentHandler) executeBatchQueue(queueID string) {
 			}
 
 			if runErr != nil {
-				if useRunResult {
+				if useRunResult && shouldPersistEinoAgentTraceAfterRunError(baseCtx) {
 					h.persistEinoAgentTraceForResume(conversationID, resultMA)
 				}
 				// 检查是否是取消错误
@@ -2632,16 +2634,6 @@ func (h *AgentHandler) executeBatchQueue(queueID string) {
 						h.logger.Warn("保存取消消息失败", zap.String("queueId", queueID), zap.String("taskId", task.ID), zap.Error(errMsg))
 					}
 				}
-				// 保存代理轨迹（如果存在）
-				if result != nil && (result.LastAgentTraceInput != "" || result.LastAgentTraceOutput != "") {
-					if err := h.db.SaveAgentTrace(conversationID, result.LastAgentTraceInput, result.LastAgentTraceOutput); err != nil {
-						h.logger.Warn("保存取消任务的代理轨迹失败", zap.String("queueId", queueID), zap.String("taskId", task.ID), zap.Error(err))
-					}
-				} else if useRunResult && resultMA != nil && (resultMA.LastAgentTraceInput != "" || resultMA.LastAgentTraceOutput != "") {
-					if err := h.db.SaveAgentTrace(conversationID, resultMA.LastAgentTraceInput, resultMA.LastAgentTraceOutput); err != nil {
-						h.logger.Warn("保存取消任务的代理轨迹失败", zap.String("queueId", queueID), zap.String("taskId", task.ID), zap.Error(err))
-					}
-				}
 				h.batchTaskManager.UpdateTaskStatusWithConversationID(queueID, task.ID, "cancelled", cancelMsg, "", conversationID)
 			} else {
 				h.logger.Error("批量任务执行失败", zap.String("queueId", queueID), zap.String("taskId", task.ID), zap.String("conversationId", conversationID), zap.Error(runErr))
diff --git a/internal/handler/eino_single_agent.go b/internal/handler/eino_single_agent.go
index 58ac331f..6801d93e 100644
--- a/internal/handler/eino_single_agent.go
+++ b/internal/handler/eino_single_agent.go
@@ -123,7 +123,14 @@ func (h *AgentHandler) EinoSingleAgentLoopStream(c *gin.Context) {
 	roleTools := prep.RoleTools
 
 	taskStatus := "completed"
-	defer h.tasks.FinishTask(conversationID, taskStatus)
+	// 仅在成功 StartTask 后再 FinishTask。若 StartTask 因 ErrTaskAlreadyRunning 失败仍 defer FinishTask，
+	// 会误删其他连接上正在运行的同会话任务，导致「第一次拦截、第二次却放行」。
+	taskOwned := false
+	defer func() {
+		if taskOwned {
+			h.tasks.FinishTask(conversationID, taskStatus)
+		}
+	}()
 
 	sendEvent("progress", "正在启动 Eino ADK 单代理（ChatModelAgent）...", map[string]interface{}{
 		"conversationId": conversationID,
@@ -168,6 +175,7 @@ func (h *AgentHandler) EinoSingleAgentLoopStream(c *gin.Context) {
 				timeoutCancel()
 				return
 			}
+			taskOwned = true
 			firstRun = false
 		} else {
 			if err := h.tasks.ResetTaskCancelForContinue(conversationID, cancelWithCause); err != nil {
@@ -203,8 +211,10 @@ func (h *AgentHandler) EinoSingleAgentLoopStream(c *gin.Context) {
 			break
 		}
 
-		h.persistEinoAgentTraceForResume(conversationID, result)
 		cause := context.Cause(baseCtx)
+		if shouldPersistEinoAgentTraceAfterRunError(baseCtx) {
+			h.persistEinoAgentTraceForResume(conversationID, result)
+		}
 		if errors.Is(cause, ErrUserInterruptContinue) {
 			reason := h.tasks.TakeInterruptContinueReason(conversationID)
 			prepNext, perr := h.prepareSessionAfterUserInterrupt(conversationID, assistantMessageID, reason, roleTools)
@@ -374,7 +384,9 @@ func (h *AgentHandler) EinoSingleAgentLoop(c *gin.Context) {
 		progressCallback,
 	)
 	if runErr != nil {
-		h.persistEinoAgentTraceForResume(prep.ConversationID, result)
+		if shouldPersistEinoAgentTraceAfterRunError(baseCtx) {
+			h.persistEinoAgentTraceForResume(prep.ConversationID, result)
+		}
 		c.JSON(http.StatusInternalServerError, gin.H{"error": runErr.Error()})
 		return
 	}
diff --git a/internal/handler/multi_agent.go b/internal/handler/multi_agent.go
index 0fd9d546..4793a28d 100644
--- a/internal/handler/multi_agent.go
+++ b/internal/handler/multi_agent.go
@@ -141,7 +141,13 @@ func (h *AgentHandler) MultiAgentLoopStream(c *gin.Context) {
 	orch := strings.TrimSpace(req.Orchestration)
 
 	taskStatus := "completed"
-	defer h.tasks.FinishTask(conversationID, taskStatus)
+	// 仅在成功 StartTask 后再 FinishTask；避免「任务已存在」分支 return 时误删正在运行的同会话任务。
+	taskOwned := false
+	defer func() {
+		if taskOwned {
+			h.tasks.FinishTask(conversationID, taskStatus)
+		}
+	}()
 
 	sendEvent("progress", "正在启动 Eino 多代理...", map[string]interface{}{
 		"conversationId": conversationID,
@@ -178,6 +184,7 @@ func (h *AgentHandler) MultiAgentLoopStream(c *gin.Context) {
 				timeoutCancel()
 				return
 			}
+			taskOwned = true
 			firstRun = false
 		} else {
 			if err := h.tasks.ResetTaskCancelForContinue(conversationID, cancelWithCause); err != nil {
@@ -215,8 +222,10 @@ func (h *AgentHandler) MultiAgentLoopStream(c *gin.Context) {
 			break
 		}
 
-		h.persistEinoAgentTraceForResume(conversationID, result)
 		cause := context.Cause(baseCtx)
+		if shouldPersistEinoAgentTraceAfterRunError(baseCtx) {
+			h.persistEinoAgentTraceForResume(conversationID, result)
+		}
 		if errors.Is(cause, ErrUserInterruptContinue) {
 			reason := h.tasks.TakeInterruptContinueReason(conversationID)
 			prepNext, perr := h.prepareSessionAfterUserInterrupt(conversationID, assistantMessageID, reason, roleTools)
@@ -388,7 +397,9 @@ func (h *AgentHandler) MultiAgentLoop(c *gin.Context) {
 		strings.TrimSpace(req.Orchestration),
 	)
 	if runErr != nil {
-		h.persistEinoAgentTraceForResume(prep.ConversationID, result)
+		if shouldPersistEinoAgentTraceAfterRunError(baseCtx) {
+			h.persistEinoAgentTraceForResume(prep.ConversationID, result)
+		}
 		h.logger.Error("Eino DeepAgent 执行失败", zap.Error(runErr))
 		errMsg := "执行失败: " + runErr.Error()
 		if prep.AssistantMessageID != "" {
diff --git a/internal/handler/task_manager.go b/internal/handler/task_manager.go
index 33e40432..55a0910d 100644
--- a/internal/handler/task_manager.go
+++ b/internal/handler/task_manager.go
@@ -17,6 +17,15 @@ var ErrUserInterruptContinue = errors.New("user interrupt with continue")
 // ErrTaskAlreadyRunning 会话已有任务正在执行
 var ErrTaskAlreadyRunning = errors.New("agent task already running for conversation")
 
+// shouldPersistEinoAgentTraceAfterRunError：Eino 相关 Run 非成功返回时，是否仍写入 last_react_* 供下轮 loadHistoryFromAgentTrace。
+// 用户主动停止（WithCancelCause(ErrTaskCancelled)）时不写入半截轨迹，避免下一轮 Plan-Execute 等因损坏/不完整 tool 上下文出现 no tool call 等异常。
+func shouldPersistEinoAgentTraceAfterRunError(baseCtx context.Context) bool {
+	if baseCtx == nil {
+		return true
+	}
+	return !errors.Is(context.Cause(baseCtx), ErrTaskCancelled)
+}
+
 // AgentTask 描述正在运行的Agent任务
 type AgentTask struct {
 	ConversationID string    `json:"conversationId"`