How to use jquery ui tooltip in Drupal7?
Try adding:

drupal_add_library('system', 'ui.tooltip');


in your theme template.php file 

/**
 * Implements hook_preprocess_html
 */
THEME_preprocess_html(&amp;$variables){
  drupal_add_library('system', 'ui.tooltip');
}


That should ensure the library is available. You can add various conditions to make it page specific as required.