diff --git a/.Lib9c.DevExtensions.Tests/Action/FaucetRuneTest.cs b/.Lib9c.DevExtensions.Tests/Action/FaucetRuneTest.cs
index 5501eb79e1..70e9e86774 100644
--- a/.Lib9c.DevExtensions.Tests/Action/FaucetRuneTest.cs
+++ b/.Lib9c.DevExtensions.Tests/Action/FaucetRuneTest.cs
@@ -113,6 +113,10 @@ private class FaucetRuneInfoGenerator : IEnumerable<object[]>
                 },
             };
 
+            /// <summary>
+            /// Returns an enumerator that iterates through the collection.
+            /// </summary>
+            /// <returns>data for each test case</returns>
             public IEnumerator<object[]> GetEnumerator()
             {
                 return _data.GetEnumerator();
diff --git a/Lib9c.DevExtensions/Manager/Contents/CreateAvatarManager.cs b/Lib9c.DevExtensions/Manager/Contents/CreateAvatarManager.cs
index c5980296ca..95f2db314d 100644
--- a/Lib9c.DevExtensions/Manager/Contents/CreateAvatarManager.cs
+++ b/Lib9c.DevExtensions/Manager/Contents/CreateAvatarManager.cs
@@ -16,8 +16,19 @@
 
 namespace Lib9c.DevExtensions.Manager.Contents
 {
+    /// <summary>
+    /// Manager class for creating an avatar for testing.
+    /// </summary>
     public static class CreateAvatarManager
     {
+        /// <summary>
+        /// Create an avatar and world state for testing.
+        /// </summary>
+        /// <param name="ctx">action context</param>
+        /// <param name="avatarAddress">avatar address</param>
+        /// <param name="states">base world state</param>
+        /// <param name="avatarState">avatar state</param>
+        /// <returns>world state with dev avatar</returns>
         public static IWorld ExecuteDevExtensions(IActionContext ctx, Address avatarAddress, IWorld states, AvatarState avatarState)
         {
             // prepare for test when executing on editor mode.
@@ -138,6 +149,9 @@ private static void EnhanceEquipmentToMaxLevel(Equipment equipment, EnhancementC
             }
         }
 
+        /// <summary>
+        /// Add test items to the avatar.
+        /// </summary>
         public static void AddTestItems(
             IActionContext ctx,
             AvatarState avatarState,