diff --git a/core/modules/text/src/Plugin/Field/FieldFormatter/TextTrimmedFormatter.php b/core/modules/text/src/Plugin/Field/FieldFormatter/TextTrimmedFormatter.php
index ed1c8c3..56c61db 100644
--- a/core/modules/text/src/Plugin/Field/FieldFormatter/TextTrimmedFormatter.php
+++ b/core/modules/text/src/Plugin/Field/FieldFormatter/TextTrimmedFormatter.php
@@ -47,9 +47,10 @@ public static function defaultSettings() {
    */
   public function settingsForm(array $form, FormStateInterface $form_state) {
     $element['trim_length'] = array(
-      '#title' => t('Trim length'),
+      '#title' => t('Body length'),
       '#type' => 'number',
       '#default_value' => $this->getSetting('trim_length'),
+      '#description' => t('The body will end at the last full sentence within this maximum number of characters.'),
       '#min' => 1,
       '#required' => TRUE,
     );
@@ -61,7 +62,7 @@ public function settingsForm(array $form, FormStateInterface $form_state) {
    */
   public function settingsSummary() {
     $summary = array();
-    $summary[] = t('Trim length: @trim_length', array('@trim_length' => $this->getSetting('trim_length')));
+    $summary[] = t('Body length: @trim_length characters', array('@trim_length' => $this->getSetting('trim_length')));
     return $summary;
   }