diff --git a/src/daemon/dispatcher.py b/src/daemon/dispatcher.py
index 82d30f9..cc35ebb 100644
--- a/src/daemon/dispatcher.py
+++ b/src/daemon/dispatcher.py
@@ -433,17 +433,14 @@ class Dispatcher:
         return "pangtong-fujunshi"
 
     async def _legacy_dispatch(self, task, action_type="", project_config=None):
-        """旧版 dispatch（兼容过渡用）"""
+        """旧版 dispatch（兼容过渡用）
+
+        v2.7.2: counter acquire/release 移到 spawn_full_agent 内部。
+        """
         decision = self._legacy_decide(task, action_type)
         level = decision["level"]
         agent_id = decision["agent_id"]
 
-        if self.counter and level in (DispatchLevel.FULL_AGENT, DispatchLevel.ESCALATE):
-            if not await self.counter.can_acquire(agent_id):
-                return {"level": level.value, "agent_id": agent_id,
-                        "session_id": None, "status": "skipped",
-                        "reason": "Agent busy (concurrent limit)"}
-
         if level == DispatchLevel.LOCAL:
             return {"level": level.value, "agent_id": "daemon",
                     "session_id": None, "status": "dispatched",
@@ -455,16 +452,11 @@ class Dispatcher:
                         "session_id": None, "status": "error",
                         "reason": "No spawner configured"}
             try:
-                if self.counter:
-                    await self.counter.acquire(agent_id)
-
                 # [v2.7.1] Mail: spawn 前系统标 working
                 is_mail_legacy = project_config.get("project_id") == "_mail" if project_config else False
                 if is_mail_legacy:
                     db_path_legacy = Path(project_config["db_path"]) if project_config and "db_path" in project_config else None
                     if not db_path_legacy or not self._mail_auto_working(task.id, db_path_legacy):
-                        if self.counter:
-                            self.counter.release(agent_id)
                         return {"level": level.value, "agent_id": agent_id,
                                 "session_id": None, "status": "error",
                                 "reason": "mail_auto_working_failed"}
@@ -484,28 +476,21 @@ class Dispatcher:
                     )
                 else:
                     message = f"Task: {task.title}"
-                # [v2.7.1] Mail: on_complete 增强
+
+                # v2.7.2: on_complete 只含业务逻辑
                 on_complete_legacy = None
                 if is_mail_legacy:
                     _t_id = task.id
-                    _a_id = agent_id
                     _m_db = db_path_legacy
                     _m_mh = task.must_haves or ""
-                    _ct = self.counter
                     _disp = self
 
                     def _mail_oc_legacy(aid, outcome):
-                        if _ct:
-                            _ct.release(aid)
                         try:
                             _disp._mail_auto_complete(_t_id, aid, _m_db, _m_mh)
                         except Exception as e:
                             logger.error("Mail %s: legacy on_complete error: %s", _t_id, e)
                     on_complete_legacy = _mail_oc_legacy
-                else:
-                    on_complete_legacy = (
-                        lambda aid, _outcome: self.counter.release(aid)
-                    ) if self.counter else None
 
                 session_id = await self.spawner.spawn_full_agent(
                     agent_id=agent_id, message=message,
@@ -518,9 +503,11 @@ class Dispatcher:
                 return {"level": level.value, "agent_id": agent_id,
                         "session_id": session_id, "status": "dispatched",
                         "reason": decision["reason"]}
+            except AgentBusyError:
+                return {"level": level.value, "agent_id": agent_id,
+                        "session_id": None, "status": "skipped",
+                        "reason": "Agent busy (concurrent limit or cooling down)"}
             except Exception as e:
-                if self.counter:
-                    self.counter.release(agent_id)
                 return {"level": level.value, "agent_id": agent_id,
                         "session_id": None, "status": "error",
                         "reason": str(e)}