diff --git a/google/oauth2/credentials.py b/google/oauth2/credentials.py
index d39848b..7572196 100644
--- a/google/oauth2/credentials.py
+++ b/google/oauth2/credentials.py
@@ -300,8 +300,9 @@
                                    generated JSON.
 
         Returns:
-            str: A JSON representation of this instance, suitable to pass to
-                 from_json().
+            str: A JSON representation of this instance. When converted into
+            a dictionary, it can be passed to from_authorized_user_info()
+            to create a new credential instance.
         """
         prep = {
             "token": self.token,