diff --git a/s05_todo_write/code.py b/s05_todo_write/code.py
index 33fda525..0529cba3 100644
--- a/s05_todo_write/code.py
+++ b/s05_todo_write/code.py
@@ -232,11 +232,8 @@ register_hook("Stop", summary_hook)
 #  agent_loop — same as s04 + nag reminder counter
 # ═══════════════════════════════════════════════════════════
 
-rounds_since_todo = 0
-
 def agent_loop(messages: list):
-    global rounds_since_todo
-    rounds_since_todo = 0  # 每轮新对话从0开始计数
+    rounds_since_todo = 0
     while True:
         # s05: nag reminder — inject if model hasn't updated todos for 3 rounds
         if rounds_since_todo >= 3 and messages:
diff --git a/s06_subagent/code.py b/s06_subagent/code.py
index f4299171..901a6368 100644
--- a/s06_subagent/code.py
+++ b/s06_subagent/code.py
@@ -312,11 +312,8 @@ register_hook("Stop", summary_hook)
 #  agent_loop — same as s05 + nag reminder, task auto-dispatches
 # ═══════════════════════════════════════════════════════════
 
-rounds_since_todo = 0
-
 def agent_loop(messages: list):
-    global rounds_since_todo
-    rounds_since_todo = 0  # 每轮新对话从0开始计数
+    rounds_since_todo = 0
     while True:
         # s05: nag reminder
         if rounds_since_todo >= 3 and messages:
diff --git a/s07_skill_loading/code.py b/s07_skill_loading/code.py
index 20c3b196..45c04313 100644
--- a/s07_skill_loading/code.py
+++ b/s07_skill_loading/code.py
@@ -356,11 +356,8 @@ register_hook("Stop", summary_hook)
 #  agent_loop — same as s05-s06 + nag reminder
 # ═══════════════════════════════════════════════════════════
 
-rounds_since_todo = 0
-
 def agent_loop(messages: list):
-    global rounds_since_todo
-    rounds_since_todo = 0  # 每轮新对话从0开始计数
+    rounds_since_todo = 0
     while True:
         if rounds_since_todo >= 3 and messages:
             messages.append({"role": "user",