diff --git a/src/Agent/Tool/ToolUseAgent.php b/src/Agent/Tool/ToolUseAgent.php
index 629e585..c8c049c 100644
--- a/src/Agent/Tool/ToolUseAgent.php
+++ b/src/Agent/Tool/ToolUseAgent.php
@@ -249,12 +249,7 @@ protected function call(?UserMessage $input = null, bool $stream = false): Gener
 
         while (true) {
             // 合并系统消息和普通消息
-            $systemMessages = $this->memory->getSystemMessages();
-            if (! empty($systemMessages)) {
-                $messages = array_merge([end($systemMessages)], $this->memory->getMessages());
-            } else {
-                $messages = $this->memory->getMessages();
-            }
+            $messages = array_merge($this->memory->getSystemMessages(), $this->memory->getMessages());
 
             if (! $stream) {
                 $response = $this->model->chat(
diff --git a/src/Memory/MemoryManager.php b/src/Memory/MemoryManager.php
index 9561d45..dac95c7 100644
--- a/src/Memory/MemoryManager.php
+++ b/src/Memory/MemoryManager.php
@@ -110,12 +110,7 @@ public function getProcessedMessages(): array
         }
 
         // 合并系统消息和普通消息
-        $systemMessages = $this->getSystemMessages();
-        if (! empty($systemMessages)) {
-            $allMessages = array_merge([end($systemMessages)], $this->getMessages());
-        } else {
-            $allMessages = $this->getMessages();
-        }
+        $allMessages = array_merge($this->getSystemMessages(), $this->getMessages());
 
         // 如果有策略，应用策略处理
         if ($this->policy !== null) {