diff --git a/core/lib/Drupal/Core/ParamConverter/ParamConverterInterface.php b/core/lib/Drupal/Core/ParamConverter/ParamConverterInterface.php
index 957dfd9..24dabb7 100644
--- a/core/lib/Drupal/Core/ParamConverter/ParamConverterInterface.php
+++ b/core/lib/Drupal/Core/ParamConverter/ParamConverterInterface.php
@@ -12,6 +12,9 @@
 
 /**
  * Interface for parameter converters.
+ *
+ * A ParamConverter is responsible for converting a route parameter
+ * to a classsed object.
  */
 interface ParamConverterInterface {