diff --git a/README.md b/README.md
index c1dafbd..82c0435 100644
--- a/README.md
+++ b/README.md
@@ -48,13 +48,13 @@ pip install yt-dlp
 
 ## Tool Documentation
 
-* **list_video_subtitles**
-  * List all available subtitles for a video
+* **list_subtitle_languages**
+  * List all available subtitle languages and their formats for a video (including auto-generated captions)
   * Inputs:
     * `url` (string, required): URL of the video
 
-* **download_video_srt**
-  * Download subtitles in SRT format
+* **download_video_subtitles**
+  * Download video subtitles in any available format. Supports both regular and auto-generated subtitles
   * Inputs:
     * `url` (string, required): URL of the video
     * `language` (string, optional): Language code (e.g., 'en', 'zh-Hant', 'ja'). Defaults to 'en'
@@ -96,3 +96,4 @@ MIT
 
 Dewei Yen
 
+
diff --git a/package.json b/package.json
index 49edd72..76da70e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@kevinwatt/yt-dlp-mcp",
-  "version": "0.6.20",
+  "version": "0.6.21",
   "description": "yt-dlp MCP Server - Download video content via Model Context Protocol",
   "keywords": [
     "mcp",
diff --git a/src/index.mts b/src/index.mts
index b6c4576..b2158cf 100644
--- a/src/index.mts
+++ b/src/index.mts
@@ -14,7 +14,7 @@ import * as path from "path";
 import { spawnPromise } from "spawn-rx";
 import { rimraf } from "rimraf";
 
-const VERSION = '0.6.20';
+const VERSION = '0.6.21';
 
 /**
  * System Configuration
@@ -100,8 +100,8 @@ server.setRequestHandler(ListToolsRequestSchema, async () => {
   return {
     tools: [
       {
-        name: "list_video_subtitles",
-        description: "List all available subtitles for a video, including auto-generated captions",
+        name: "list_subtitle_languages",
+        description: "List all available subtitle languages and their formats for a video (including auto-generated captions)",
         inputSchema: {
           type: "object",
           properties: {
@@ -242,13 +242,18 @@ async function listSubtitles(url: string): Promise<string> {
         "--list-subs",         // 列出一般字幕
         "--write-auto-sub",    // 包含自動生成的字幕
         "--skip-download",
+        "--verbose",           // 添加詳細輸出
         url
       ],
       { cwd: tempDirectory }
     );
+
+    // 如果沒有一般字幕，添加說明
+    if (result.includes("has no subtitles")) {
+      return "Regular subtitles: None\n\nAuto-generated subtitles: Available in multiple languages";
+    }
     return result;
   } catch (error) {
-    // 直接傳遞 yt-dlp 的錯誤訊息
     throw error;
   } finally {
     await safeCleanup(tempDirectory);
@@ -268,7 +273,6 @@ async function downloadSubtitles(url: string, language: string = "en"): Promise<
       throw new Error('Invalid language code');
     }
 
-    // 下載字幕，同時支援一般字幕和自動生成的字幕
     try {
       const result = await spawnPromise(
         "yt-dlp",
@@ -278,6 +282,7 @@ async function downloadSubtitles(url: string, language: string = "en"): Promise<
           "--sub-lang", language,
           "--convert-subs", "srt",
           "--skip-download",
+          "--verbose",           // 添加詳細輸出
           url
         ],
         { cwd: tempDirectory }
@@ -293,7 +298,7 @@ async function downloadSubtitles(url: string, language: string = "en"): Promise<
     
     // 過濾出字幕文件
     const subtitleFiles = files.filter(file => 
-      file.endsWith('.srt')
+      file.endsWith('.srt') || file.endsWith('.vtt')
     );
 
     if (subtitleFiles.length === 0) {
@@ -494,10 +499,10 @@ server.setRequestHandler(
       resolution?: string;
     };
 
-    if (toolName === "list_video_subtitles") {
+    if (toolName === "list_subtitle_languages") {
       return handleToolExecution(
         () => listSubtitles(args.url),
-        "Error listing subtitles"
+        "Error listing subtitle languages"
       );
     } else if (toolName === "download_video_subtitles") {
       return handleToolExecution(