feat：完成重构和测试

app/agent/tools.py

@@ -10,6 +10,7 @@ from langchain.agents import AgentState
 from langchain.tools import ToolRuntime, tool
 from langchain_core.messages import ToolMessage
 from langgraph.types import Command
+from pydantic import Field
 
 from app.actions.batch import BatchError, run_batch
 from app.schemas.actions import Action, AddAction
@@ -63,7 +64,12 @@ def _result_text(actions: list[Action]) -> str:
 
 @tool
 def apply_actions(
-    actions: list[Action], runtime: ToolRuntime[ScreenAgentContext]
+    actions: Annotated[
+        list[Action],
+        # 空的一批会清掉之前成功的结果；参数校验失败不改状态，之前的结果保留
+        Field(min_length=1, description="至少一个动作；不需要修改时不要调用，直接回复"),
+    ],
+    runtime: ToolRuntime[ScreenAgentContext],
 ) -> Command:
     """提交本次要对大屏做的全部修改