diff --git a/core/includes/entity.api.php b/core/includes/entity.api.php
index 190658b..d385088 100644
--- a/core/includes/entity.api.php
+++ b/core/includes/entity.api.php
@@ -540,6 +540,9 @@ function hook_entity_field_access($operation, $field, $account) {
 /**
  * Alters the default access behaviour for a given field.
  *
+ * Use this hook to override access grants from another module. Note that the
+ * default access flag is masked under the umbrella of the system module.
+ *
  * @param array $grants
  *   An array of grants gathered by hook_entity_field_access(). The array is
  *   keyed by the module that defines the field's access control; the values are
@@ -554,7 +557,11 @@ function hook_entity_field_access($operation, $field, $account) {
 function hook_entity_field_access_alter(array &$grants, array $context) {
   $field = $context['field'];
   if ($field->getName() == 'field_of_interest' && $grants['node'] === FALSE) {
-    // Override node module's restriction to no opinion.
+    // Override node module's restriction to no opinion. We don't want to
+    // provide our own access hook, we only want to take out node module's part
+    // in the access handling of this field. We also don't want to switch node
+    // module's grant to TRUE, because the grants of other modules should still
+    // decide on their own if this field is accessible or not.
     $grants['node'] = NULL;
   }
 }
diff --git a/core/lib/Drupal/Core/Entity/Field/Type/Field.php b/core/lib/Drupal/Core/Entity/Field/Type/Field.php
index 260e1fd..39d4d2e 100644
--- a/core/lib/Drupal/Core/Entity/Field/Type/Field.php
+++ b/core/lib/Drupal/Core/Entity/Field/Type/Field.php
@@ -293,14 +293,16 @@ public function access($operation = 'view', User $account = NULL) {
     if (!isset($account) && $user->uid) {
       $account = user_load($user->uid);
     }
+    // Get the default access restriction that lives within this field.
     $access = $this->defaultAccess($operation, $account);
-    // Invoke hook and collect grants/denies for field access. Our default
-    // access flag is masked under the umbrella of the system module.
+    // Invoke hook and collect grants/denies for field access from other
+    // modules. Our default access flag is masked under the umbrella of the
+    // system module.
     $grants = array('system' => $access);
     foreach (module_implements('entity_field_access') as $module) {
       $grants = array_merge($grants, array($module => module_invoke($module, 'entity_field_access', $operation, $this, $account)));
     }
-    // Allow other modules to alter the returned grants/denies.
+    // Also allow modules to alter the returned grants/denies.
     $context = array(
       'operation' => $operation,
       'field' => $this,
@@ -324,7 +326,9 @@ public function access($operation = 'view', User $account = NULL) {
    * Contains the default access logic of this field.
    *
    * See \Drupal\Core\TypedData\AccessibleInterface::access() for the parameter
-   * doucmentation.
+   * doucmentation. This method can be overriden by field sub classes to provide
+   * a different default access logic. That allows them to inherit the complete
+   * access() method which contains the access hook invocation logic.
    *
    * @return bool
    *   TRUE if access to this field is allowed per default, FALSE otherwise.