diff --git a/token.module b/token.module
index b683c70..1d430e8 100644
--- a/token.module
+++ b/token.module
@@ -271,11 +271,155 @@ function token_form_block_admin_configure_alter(&$form, $form_state) {
 
 /**
  * Implements hook_widget_form_alter().
+ *
+ * Replaces tokens in field descriptions of (primaryly) single-value'd
+ * instances.
  */
 function token_field_widget_form_alter(&$element, &$form_state, $context) {
-  if (!empty($element['#description']) && !empty($context['instance']['description'])) {
-    $element['#description'] = filter_xss_admin(token_replace($context['instance']['description']));
+  if (!empty($context['instance']['description'])) {
+    $original_description = $context['instance']['description'];
+
+    // Avoid expensive regular expression checks in token_scan() and
+    // field_filter_xss()/filter_xss() - and at lot of other work - if
+    // unnecessary (no square bracket: no tokens).
+    if (strpos(' ' . $original_description, '[')) {
+      $modified_description = field_filter_xss(token_replace($original_description));
+
+      // Do we need to work at all?
+      if ($modified_description != $original_description) {
+
+        // Find the description(s):
+        $field_type = $context['field']['type'];
+
+        // File fields are pretty non-standard.
+        $file_cardinality_single = FALSE;
+
+        // Find the $element array(s) listing description.
+        // Use safer array_key_exists() instead of empty(); form arrays come in
+        // many shapes and sizes.
+        if (array_key_exists('value', $element) && array_key_exists('#description', $element['value'])) {
+          // text and number_ fields have a #description in a value bucket.
+          // Their single row instances' ['value']['#description'] is non-empty
+          // (and that one is used in widget rendering), whereas any/multiple
+          // rows instances' ['value']['#description'] is empty.
+          $props =& $element['value'];
+          // text and number_ fields single row instances got #description in
+          // root too; it's usually not used but let's play it safe.
+          if (array_key_exists('#description', $element)) {
+            $element['#description'] = $modified_description;
+          }
+        }
+        elseif (array_key_exists('#description', $element)) {
+          // list_ types.
+          $props =& $element;
+        }
+        elseif (array_key_exists(0, $element) && array_key_exists('#description', $element[0])) {
+          // Single instance file has no props in $element root.
+          $file_cardinality_single = TRUE;
+          $props =& $element[0];
+        }
+        else {
+          // Unsupported element structure.
+          return;
+        }
+
+        switch ($field_type) {
+          case 'file':
+          case 'image':
+            // Multi instance file fields have description on instances as well
+            // as the overall field.
+            if (!$file_cardinality_single) {
+              $limit = 100;
+              for ($i = 0; $i < $limit; ++$i) {
+                if (!empty($element[$i]) && array_key_exists('#description', $element[$i])) {
+                  $element[$i]['#description'] = $modified_description;
+                }
+                else {
+                  break;
+                }
+              }
+            }
+            // Single instance (cardinality:1) file fields' #description get
+            // file size and extensions info appended prior to this phase.
+            elseif (!empty($props['#description']) && strpos($props['#description'], '<br')) {
+              $a = explode('<br', $props['#description']);
+              $a[0] = $modified_description;
+              $props['#description'] = join('<br', $a);
+
+              // Done with this one, get out before generic assignment.
+              return;
+            }
+            break;
+        }
+
+        $props['#description'] = $modified_description;
+      }
+    }
+  }
+}
+
+/**
+ * Implements hook_preprocess_HOOK().
+ * Implements hook_preprocess_field_multiple_value_form().
+ *
+ * Replaces tokens in field descriptions of multi-value'd instances.
+ */
+function token_preprocess_field_multiple_value_form(&$variables) {
+  // Avoid expensive regular expression checks in token_scan() and
+  // field_filter_xss()/filter_xss() - and at lot of other work - if
+  // unnecessary (no square bracket: no tokens).
+  if (!empty($variables['element']['#description']) && strpos(' ' . $variables['element']['#description'], '[')) {
+
+    // Get unfiltered description from field_info_instance().
+    // Thus we need to establish field name, entity type and bundle.
+    if (!empty($variables['element'][0])) {
+      $element =& $variables['element'];
+
+      if (!empty($element['#field_name'])) {
+        $field_name = $element['#field_name'];
+
+        if (!empty($element[0]['#entity_type']) && !empty($element[0]['#bundle']) ) {
+          $entity_type = $element[0]['#entity_type'];
+          $bundle = $element[0]['#bundle'];
+        }
+        // Number fields haven't got entity type and bundle on
+        // $variables['element'][0].
+        elseif (!empty($element[0]['value']['#entity_type']) && !empty($element[0]['value']['#bundle'])) {
+          $entity_type = $element[0]['value']['#entity_type'];
+          $bundle = $element[0]['value']['#bundle'];
+        }
+        // Unsupported field type.
+        else {
+          unset($element); // Clear ref.
+
+          return;
+        }
+
+        // field_collection_item always reports itself as bundle.
+        if ($bundle == $field_name) {
+          if (!empty($variables['element']['#field_parents'][0])) {
+            $bundle = $variables['element']['#field_parents'][0];
+          }
+          // field_collection_item will also reports it's parent as itself
+          // when attached directly to entity/node (not nested in another
+          // field collection).
+          if ($bundle == $field_name) {
+            // Our options exhausted - field type + cardinality not supported.
+            unset($element); // Clear ref.
+
+            return;
+          }
+        }
+        $instance_info = field_info_instance($entity_type, $field_name, $bundle);
+        if ($instance_info && !empty($instance_info['description'])) {
+          $element['#description'] = field_filter_xss(token_replace($instance_info['description']));
+        }
+      }
+      unset($element); // Clear ref.
+    }
   }
+  // There's another description in $variables['element'][0]['#description']
+  // but haven't found a field type that gets that one rendered.
 }
 
 /**