diff --git a/apps/api/src/services/approval_execution.py b/apps/api/src/services/approval_execution.py
index b8d1c5de..3de07695 100644
--- a/apps/api/src/services/approval_execution.py
+++ b/apps/api/src/services/approval_execution.py
@@ -144,14 +144,57 @@ class ApprovalExecutionService:
         namespace = parsed.namespace
 
         if operation_type is None or resource_name is None:
+            # 2026-04-19 ogt + Claude Opus 4.7: 區分 NO_ACTION vs 真解析失敗
+            # NO_ACTION 是 AI 刻意選的「純調查不破壞」,不該誤標 EXECUTION_FAILED
+            # 污染 auto_execute 成功率 KPI (MASTER §7.1 #11)
+            _action_upper = (approval.action or "").upper()
+            _is_no_action = (
+                "NO_ACTION" in _action_upper
+                or "NO-ACTION" in _action_upper
+                or "NOACTION" in _action_upper
+                or "(未設)" in approval.action
+                or _action_upper.startswith("OBSERVE")
+                or _action_upper.startswith("INVESTIGATE")
+            )
+
+            if _is_no_action:
+                logger.info(
+                    "background_execution_noop",
+                    approval_id=str(approval.id),
+                    action=approval.action,
+                    reason="NO_ACTION - 純調查/觀察類,不執行破壞動作",
+                )
+                # 標為 SUCCESS (觀察/調查本身就是成功完成)
+                await service.update_execution_status(approval.id, success=True)
+                await timeline.add_event(
+                    event_type="exec",
+                    status="success",
+                    title="✅ 純觀察類動作完成 (NO_ACTION)",
+                    description=f"Action: {approval.action[:120]}",
+                    actor="leWOOOgo",
+                    actor_role="executor",
+                    approval_id=str(approval.id),
+                )
+                # 執行結果 reply 原告警卡片
+                asyncio.create_task(
+                    self._push_execution_result_to_alert(
+                        approval, success=True, error=None,
+                    )
+                )
+                return True  # NO_ACTION 視為成功完成
+
+            # 真解析失敗 (非 NO_ACTION)
             logger.warning(
                 "background_execution_skip",
                 approval_id=str(approval.id),
                 reason="Could not parse operation type from action",
                 action=approval.action,
             )
-            # Phase 5: 更新資料庫狀態
-            await service.update_execution_status(approval.id, success=False)
+            # Phase 5: 更新資料庫狀態 + 帶 error_message (P0.2)
+            await service.update_execution_status(
+                approval.id, success=False,
+                error_message=f"Could not parse operation type from action: {approval.action[:150]}",
+            )
             await timeline.add_event(
                 event_type="exec",
                 status="error",