diff --git a/server/service/agent/chat-engine.ts b/server/service/agent/chat-engine.ts
index 8297fb2..5954f17 100644
--- a/server/service/agent/chat-engine.ts
+++ b/server/service/agent/chat-engine.ts
@@ -251,9 +251,11 @@ export async function executeChat(params: ChatEngineParams): Promise<ChatEngineR
   if (user) {
     const memoryContext = await getMemoryContext(user.id);
     if (memoryContext) {
+      const memoryInstruction =
+        "\n\n以下 <memory> 标签内是你的持久记忆，已注入上下文。回答问题时优先参考这些记忆，不要重复调用 document 工具读取已有记忆。";
       systemPrompt = systemPrompt
-        ? `${systemPrompt}\n\n${memoryContext}`
-        : memoryContext;
+        ? `${systemPrompt}${memoryInstruction}\n${memoryContext}`
+        : `${memoryInstruction}\n${memoryContext}`;
     }
   }