diff --git a/xiaoqu-agent-service/src/main/java/me/iiv/agent/mcp/tool/ChangesTools.java b/xiaoqu-agent-service/src/main/java/me/iiv/agent/mcp/tool/ChangesTools.java
index bea9bc9..de6e268 100644
--- a/xiaoqu-agent-service/src/main/java/me/iiv/agent/mcp/tool/ChangesTools.java
+++ b/xiaoqu-agent-service/src/main/java/me/iiv/agent/mcp/tool/ChangesTools.java
@@ -5,6 +5,7 @@ import me.iiv.agent.mcp.McpErrorCode;
 import me.iiv.agent.mcp.ToolCallException;
 import me.iiv.agent.mcp.XqTool;
 import me.iiv.agent.mcp.sync.BatteryFaultsSyncEntity;
+import me.iiv.agent.mcp.sync.BuildingsSyncEntity;
 import me.iiv.agent.mcp.sync.ChangesEngine;
 import me.iiv.agent.mcp.sync.ContractsSyncEntity;
 import me.iiv.agent.mcp.sync.DeviceLifecyclesSyncEntity;
@@ -34,9 +35,9 @@ import java.util.Map;
 
 /**
  * 增量同步工具（REQ-20260911-0013；P2 域扩展于 REQ-20260902-0002）：
- * users/properties/contracts/repayment-targets/repayment-details/mall-orders/
+ * users/properties/buildings/contracts/repayment-targets/repayment-details/mall-orders/
  * device-lifecycles/battery-faults/devices/withdraw-orders/relocation-orders/
- * install-orders 十二个 changes 工具，
+ * install-orders 十三个 changes 工具，
  * 协议（snapshot/cursor/tombstone/sync_token）由 ChangesEngine 统一实现。
  * 数据域硬约束：本类不声明 tenant_id/scope 入参，数据域只能从 Token 推导；
  * GuardedToolCallback 对 *.changes.list 工具的原始入参做二次拦截，传 tenant_id/scope 一律拒绝。
diff --git a/xiaoqu-agent-service/src/test/java/me/iiv/agent/mcp/tool/ChangesToolsTest.java b/xiaoqu-agent-service/src/test/java/me/iiv/agent/mcp/tool/ChangesToolsTest.java
index 7019b25..d8d317f 100644
--- a/xiaoqu-agent-service/src/test/java/me/iiv/agent/mcp/tool/ChangesToolsTest.java
+++ b/xiaoqu-agent-service/src/test/java/me/iiv/agent/mcp/tool/ChangesToolsTest.java
@@ -41,8 +41,9 @@ class ChangesToolsTest {
                 callback -> callback.getToolDefinition().name(),
                 callback -> callback.getToolDefinition().inputSchema()));
 
-        assertEquals(14, schemas.size());
-        for (String name : new String[]{"users.changes.list", "properties.changes.list", "contracts.changes.list",
+        assertEquals(15, schemas.size());
+        for (String name : new String[]{"users.changes.list", "properties.changes.list", "buildings.changes.list",
+                "contracts.changes.list",
                 "repayment-targets.changes.list", "repayment-details.changes.list",
                 "mall-orders.changes.list", "device-lifecycles.changes.list", "battery-faults.changes.list",
                 "devices.changes.list", "withdraw-orders.changes.list", "relocation-orders.changes.list",