Provide a description entity key especially for use with exportable entites (e.g. as seen in node types)

+++ b/entity.module
@@ -519,6 +519,24 @@ function entity_has_status($entity_type, $entity, $status) {
+ * Returns the description of a given entity if the entity type supports
+ * descriptions and a description is set.

First line of comments may not be wrapped, but may exceed 80chars.

+++ b/entity.module
@@ -519,6 +519,24 @@ function entity_has_status($entity_type, $entity, $status) {
+function entity_description($entity_type, $entity) {

I don't think we need a helper function for reading the description key. I don't think it's often used in code and in the admin-ui it's more performant to read out the value out of the there existing entity info anyway.

+++ b/entity.module
@@ -519,6 +519,24 @@ function entity_has_status($entity_type, $entity, $status) {
+  $description_key = empty($info['entity key']['description']) ? 'description' : $info['entity keys']['description'];

This should default to no description key.

+++ b/includes/entity.ui.inc
@@ -664,9 +666,14 @@ function entity_ui_validate_machine_name($element, &$form_state) {
+  // In order to display the description properly a float is required.
+  drupal_add_css(drupal_get_path('module', 'entity') . '/entity.admin.css');

The CSS got already added via #attached, not?

+++ b/includes/entity.ui.inc
@@ -664,9 +666,14 @@ function entity_ui_validate_machine_name($element, &$form_state) {
+  // In order to display the description properly a float is required.
+  drupal_add_css(drupal_get_path('module', 'entity') . '/entity.admin.css');

I don't think we need extra CSS here at all. Node module's content types list doesn't need any AFAICT.

updated patch.

I've taken out the CSS. I can't see any difference with it there at all.

Ahhh.

But entity API's admin UI doesn't do tabledrags. (Yet -- I filed a feature request for that: #1659456: support for hierarchical entities.)
So currently, if an entity module turns this into a tabledrag it's surely up to that module to tweak the CSS as needed.

The 7 year old patch in #6 does not apply to the latest entity 7.x-1.x-dev.

Checking patch entity.api.php...
error: while searching for:
 *   - status: (optional) The name of the entity property used by the entity
 *     CRUD API to save the exportable entity status using defined bit flags.
 *     Defaults to 'status'. See entity_has_status().
 * - export: (optional) An array of information used for exporting. For ctools
 *   exportables compatibility any export-keys supported by ctools may be added
 *   to this array too.

error: patch failed: entity.api.php:74
error: entity.api.php: patch does not apply

Checking patch entity.module...
error: while searching for:
      'template' => 'entity',
    ),
    'entity_ui_overview_item' => array(
      'variables' => array('label' => NULL, 'entity_type' => NULL, 'url' => FALSE, 'name' => FALSE),
      'file' => 'includes/entity.ui.inc'
    ),
  );

error: patch failed: entity.module:857
error: entity.module: patch does not apply

Checking patch includes/entity.ui.inc...
Hunk #1 succeeded at 270 (offset 5 lines).
error: while searching for:
  if ($variables['name']) {
    $output .= ' <small> (' . t('Machine name') . ': ' . check_plain($variables['name']) . ')</small>';
  }
  return $output;
}

error: patch failed: includes/entity.ui.inc:668
error: includes/entity.ui.inc: patch does not apply

@Chris Matthews, Please review below-attached patch for latest entity 7.x-1.x-dev and kindly share your feedback on the same. thanks