Hide Formatting Guidelines on Drupal's Comment Form

Need to hide the formatting guidelines and description that show up by default on Drupal's comment form? Try something like this:

function mymodule_form_alter(&$form, &$form_state, $form_id) {
  switch ($form_id) {
    case "comment_form":
      // begin: hide 'filtered html' input format guidelines and description
      unset($form['comment_filter']['format']['format']['guidelines']['#value']);
      unset($form['comment_filter']['format'][2]['#value']);
      // end
    break;
  }
}