fix: 恢复 queryInternalDocs 的原始工具描述

保留原始 @Tool description，仅在 Java 层面标记 @Deprecated。
这样可以保留完整的工具提示词用于后续对比分析。

src/main/java/com/superbiz/agent/agent/tool/InternalDocsTools.java

@@ -53,9 +53,10 @@ public class InternalDocsTools {
      * @deprecated 请使用 {@link com.superbiz.agent.tool.LookupKnowledgeTool#lookupKnowledge(String)} 替代
      */
     @Deprecated
-    @Tool(description = "[DEPRECATED] Use lookup_knowledge instead. " +
+    @Tool(description = "Use this tool to search internal documentation and knowledge base for relevant information. " +
-            "This tool performs semantic search only. " +
+            "It performs RAG (Retrieval-Augmented Generation) to find similar documents and extract processing steps. " +
-            "lookup_knowledge provides L0 exact match + L1 semantic search with better performance.")
+            "This is useful when you need to understand internal procedures, best practices, or step-by-step guides " +
+            "stored in the company's documentation.")
     public String queryInternalDocs(
             @ToolParam(description = "Search query describing what information you are looking for") 
             String query) {