diff --git a/websocket-sharp/Server/HttpServer.cs b/websocket-sharp/Server/HttpServer.cs
index c5dc45d3..4d7d083f 100644
--- a/websocket-sharp/Server/HttpServer.cs
+++ b/websocket-sharp/Server/HttpServer.cs
@@ -1124,20 +1124,53 @@ namespace WebSocketSharp.Server
     }
 
     /// <summary>
-    /// Adds a WebSocket service with the specified behavior and <paramref name="path"/>.
+    /// Adds a WebSocket service with the specified behavior and
+    /// <paramref name="path"/>.
     /// </summary>
     /// <remarks>
-    /// This method converts <paramref name="path"/> to URL-decoded string,
-    /// and removes <c>'/'</c> from tail end of <paramref name="path"/>.
+    /// <paramref name="path"/> is converted to a URL-decoded string and
+    /// '/' is trimmed from the end of the converted string if any.
     /// </remarks>
     /// <param name="path">
-    /// A <see cref="string"/> that represents the absolute path to the service to add.
+    /// A <see cref="string"/> that represents an absolute path to
+    /// the service to add.
     /// </param>
     /// <typeparam name="TBehaviorWithNew">
-    /// The type of the behavior of the service to add. The TBehaviorWithNew must inherit
-    /// the <see cref="WebSocketBehavior"/> class, and must have a public parameterless
-    /// constructor.
+    ///   <para>
+    ///   The type of the behavior for the service.
+    ///   </para>
+    ///   <para>
+    ///   It must inherit the <see cref="WebSocketBehavior"/> class and
+    ///   must have a public parameterless constructor.
+    ///   </para>
     /// </typeparam>
+    /// <exception cref="ArgumentNullException">
+    /// <paramref name="path"/> is <see langword="null"/>.
+    /// </exception>
+    /// <exception cref="ArgumentException">
+    ///   <para>
+    ///   <paramref name="path"/> is an empty string.
+    ///   </para>
+    ///   <para>
+    ///   -or-
+    ///   </para>
+    ///   <para>
+    ///   <paramref name="path"/> is not an absolute path.
+    ///   </para>
+    ///   <para>
+    ///   -or-
+    ///   </para>
+    ///   <para>
+    ///   <paramref name="path"/> includes either or both
+    ///   query and fragment components.
+    ///   </para>
+    ///   <para>
+    ///   -or-
+    ///   </para>
+    ///   <para>
+    ///   <paramref name="path"/> is already in use.
+    ///   </para>
+    /// </exception>
     public void AddWebSocketService<TBehaviorWithNew> (string path)
       where TBehaviorWithNew : WebSocketBehavior, new ()
     {