define more submission results permissions

I would like to define more permissions on each submission result local menu tab ie analysis, download, table

Here is my custom module, first implement hook_permission to define new user permission and then implement hook_menu_alter to override existing access callback

function webform_custom_permission() {
  return array(
    'access webform results analysis' => array(
       'title' => t('Access webform results analysis'),
       'description' => t('Grants access to the "Results analysis" tab'),
    ),
    'access webform results download' => array(
       'title' => t('Access webform results download'),
       'description' => t('Grants access to the "Results download" tab'),
    ),
  );
}

function webform_custom_menu_alter(&$items) {
  $items['node/%/webform-results/download']['access callback'] = 'user_access';
  $items['node/%/webform-results/download']['access arguments'] = array('access webform results download');
}

I checked the new permission for a test user on admin/people/permissions
however the download local tab still no show.

What I am missed ?