diff --git a/engine/utils/function_calling/common.h b/engine/utils/function_calling/common.h
index d01f22423..eb0d45cf4 100644
--- a/engine/utils/function_calling/common.h
+++ b/engine/utils/function_calling/common.h
@@ -158,6 +158,10 @@ inline void UpdateMessages(std::string& system_prompt,
         tool_choice["function"]["name"].asString() +
         "' to answer the user's question.";
   }
+  bool parallel_tool_calls = request->get("parallel_tool_calls", true).asBool();
+  if (!parallel_tool_calls) {
+    system_prompt += "\n\nNow this is your first priority: You must call the only one function at a time.";
+  }
 
   bool tools_call_in_user_message =
       request->get("tools_call_in_user_message", false).asBool();
diff --git a/engine/utils/function_calling/llama3.1.h b/engine/utils/function_calling/llama3.1.h
index 5c2e6ffdb..a0ebe941e 100644
--- a/engine/utils/function_calling/llama3.1.h
+++ b/engine/utils/function_calling/llama3.1.h
@@ -30,14 +30,15 @@ Here is an example,
 Reminder:
 - Function calls MUST follow the specified format
 - Required parameters MUST be specified
-- Only call one function at a time
+- You can call one or more functions at a time
 - Put the entire function call reply on one line
 - Always add your sources when using search results to answer the user query
-- If can not find correct parameters corresponding to function, ask user again to provide.
+- If you can not find correct parameters or arguments corresponding to function in the user's message, ask user again to provide, do not make assumptions.
 - No explanation are needed when calling a function.
 
 You are a helpful assistant.
 )";
 
-constexpr auto tool_role = "<|eot_id|>\n<|start_header_id|>ipython<|end_header_id|>\n";
+constexpr auto tool_role =
+    "<|eot_id|>\n<|start_header_id|>ipython<|end_header_id|>\n";
 }  // namespace function_calling_llama3_1_utils