diff --git a/agentscope-core/src/main/java/io/agentscope/core/memory/StaticLongTermMemoryHook.java b/agentscope-core/src/main/java/io/agentscope/core/memory/StaticLongTermMemoryHook.java
index b57bb5433..0a01a00c1 100644
--- a/agentscope-core/src/main/java/io/agentscope/core/memory/StaticLongTermMemoryHook.java
+++ b/agentscope-core/src/main/java/io/agentscope/core/memory/StaticLongTermMemoryHook.java
@@ -156,8 +156,8 @@ private Mono<PreCallEvent> handlePreCall(PreCallEvent event) {
 
                             // Inject memory message at the beginning
                             List<Msg> enhancedMessages = new ArrayList<>();
-                            enhancedMessages.addAll(inputMessages);
                             enhancedMessages.add(memoryMsg);
+                            enhancedMessages.addAll(inputMessages);
                             event.setInputMessages(enhancedMessages);
 
                             return Mono.just(event);
diff --git a/agentscope-core/src/main/java/io/agentscope/core/tool/ToolGroupManager.java b/agentscope-core/src/main/java/io/agentscope/core/tool/ToolGroupManager.java
index c6d4c0fcf..9b4fa72b3 100644
--- a/agentscope-core/src/main/java/io/agentscope/core/tool/ToolGroupManager.java
+++ b/agentscope-core/src/main/java/io/agentscope/core/tool/ToolGroupManager.java
@@ -21,6 +21,7 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -33,7 +34,7 @@ class ToolGroupManager {
 
     private final Map<String, ToolGroup> toolGroups = new ConcurrentHashMap<>(); // group -> tools
     private final Map<String, Set<String>> tools = new ConcurrentHashMap<>(); // tool -> groups
-    private List<String> activeGroups = new ArrayList<>();
+    private final List<String> activeGroups = new CopyOnWriteArrayList<>();
 
     /**
      * Create tool groups and record them in the manager.
@@ -324,7 +325,8 @@ public List<String> getActiveGroups() {
      * @param activeGroups List of group names to mark as active
      */
     public void setActiveGroups(List<String> activeGroups) {
-        this.activeGroups = new ArrayList<>(activeGroups);
+        this.activeGroups.clear();
+        this.activeGroups.addAll(activeGroups);
 
         // Mark corresponding groups as active
         for (String groupName : activeGroups) {
@@ -374,7 +376,8 @@ void copyTo(ToolGroupManager target) {
         }
 
         // Copy activeGroups list
-        target.activeGroups = new ArrayList<>(this.activeGroups);
+        target.activeGroups.clear();
+        target.activeGroups.addAll(this.activeGroups);
     }
 
     private boolean removeGroupFromToolIndex(String toolName, String groupName) {
diff --git a/agentscope-core/src/main/java/io/agentscope/core/util/MessageUtils.java b/agentscope-core/src/main/java/io/agentscope/core/util/MessageUtils.java
index c7839f2d6..f28c3a627 100644
--- a/agentscope-core/src/main/java/io/agentscope/core/util/MessageUtils.java
+++ b/agentscope-core/src/main/java/io/agentscope/core/util/MessageUtils.java
@@ -19,6 +19,7 @@
 import io.agentscope.core.message.MsgRole;
 import io.agentscope.core.message.ToolUseBlock;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * Utility methods for message processing and extraction.
@@ -51,7 +52,7 @@ public static List<ToolUseBlock> extractRecentToolCalls(List<Msg> messages, Stri
 
         for (int i = messages.size() - 1; i >= 0; i--) {
             Msg msg = messages.get(i);
-            if (msg.getRole() == MsgRole.ASSISTANT && msg.getName().equals(agentName)) {
+            if (msg.getRole() == MsgRole.ASSISTANT && Objects.equals(msg.getName(), agentName)) {
                 List<ToolUseBlock> toolCalls = msg.getContentBlocks(ToolUseBlock.class);
                 if (!toolCalls.isEmpty()) {
                     return toolCalls;
diff --git a/agentscope-core/src/test/java/io/agentscope/core/memory/StaticLongTermMemoryHookTest.java b/agentscope-core/src/test/java/io/agentscope/core/memory/StaticLongTermMemoryHookTest.java
index 37417ee26..14a2c8e46 100644
--- a/agentscope-core/src/test/java/io/agentscope/core/memory/StaticLongTermMemoryHookTest.java
+++ b/agentscope-core/src/test/java/io/agentscope/core/memory/StaticLongTermMemoryHookTest.java
@@ -138,13 +138,13 @@ void testOnEventWithPreReasoningEventAndRetrievedMemories() {
                         resultEvent -> {
                             List<Msg> messages = resultEvent.getInputMessages();
                             assertEquals(2, messages.size());
-                            assertEquals(MsgRole.SYSTEM, messages.get(1).getRole());
+                            assertEquals(MsgRole.SYSTEM, messages.get(0).getRole());
                             assertTrue(
-                                    messages.get(1)
+                                    messages.get(0)
                                             .getTextContent()
                                             .contains("<long_term_memory>"));
                             assertTrue(
-                                    messages.get(1)
+                                    messages.get(0)
                                             .getTextContent()
                                             .contains("User prefers dark mode"));
                         })