diff --git a/src/prim-types.hh b/src/prim-types.hh
index a0d921d0..11ca06dc 100644
--- a/src/prim-types.hh
+++ b/src/prim-types.hh
@@ -1642,6 +1642,12 @@ class TypedAttribute {
 
   void set_value_empty() { _value_empty = true; }
 
+  //
+  // Check if the attribute is authored, but no value(including ValueBlock) assigned.
+  // e.g.
+  //
+  // float myval;
+  //
   bool is_value_empty() const {
     if (has_connections()) {
       return false;
@@ -1658,7 +1664,7 @@ class TypedAttribute {
     return _value_empty;
   }
 
-  // value set?
+  // The attribute authroed?
   bool authored() const {
     if (_attrib) {
       return true;
@@ -1803,6 +1809,12 @@ class TypedAttributeWithFallback {
 
   bool has_connections() const { return _paths.size(); }
 
+  //
+  // Check if the attribute is authored, but no value(including ValueBlock) assigned.
+  // e.g.
+  //
+  // float myval;
+  //
   bool is_value_empty() const {
     if (has_connections()) {
       return false;