优化查询代码，优化工具代码

backend/app/tools/subgraph.py

@@ -0,0 +1,42 @@
+"""
+子图工具 - 通讯录、词典、新闻分析等
+"""
+
+from langchain_core.tools import tool
+from backend.app.logger import info
+
+
+async def _call_subgraph(builder_fn, state_cls, query: str) -> str:
+    """通用子图调用"""
+    try:
+        graph = builder_fn().compile()
+        state = state_cls(user_query=query)
+        result = await graph.ainvoke(state)
+        return result.get("final_result", "执行完成")
+    except Exception as e:
+        info(f"[Tool] 子图调用失败: {e}")
+        return f"执行失败: {str(e)}"
+
+
+@tool
+async def contact_lookup(query: str) -> str:
+    """查询通讯录"""
+    from backend.app.subgraphs.contact.graph import build_contact_subgraph
+    from backend.app.subgraphs.contact.state import ContactState
+    return await _call_subgraph(build_contact_subgraph, ContactState, query)
+
+
+@tool
+async def dictionary_lookup(word: str) -> str:
+    """查询词典/翻译"""
+    from backend.app.subgraphs.dictionary.graph import build_dictionary_subgraph
+    from backend.app.subgraphs.dictionary.state import DictionaryState
+    return await _call_subgraph(build_dictionary_subgraph, DictionaryState, word)
+
+
+@tool
+async def news_analysis(topic: str) -> str:
+    """分析新闻热点"""
+    from backend.app.subgraphs.news_analysis.graph import build_news_analysis_subgraph
+    from backend.app.subgraphs.news_analysis.state import NewsAnalysisState
+    return await _call_subgraph(build_news_analysis_subgraph, NewsAnalysisState, topic)