Documentation for hook_token_info_alter is incorrect

function hook_token_info_alter(&$data) {
  // Modify description of node tokens for our site.
  $node['nid'] = array(
    'name' => t("Node ID"),
    'description' => t("The unique ID of the article."),
  );
  $node['title'] = array(
    'name' => t("Title"),
    'description' => t("The title of the article."),
  );

  // Chained tokens for nodes.
  $node['created'] = array(
    'name' => t("Date created"),
    'description' => t("The date the article was posted."),
    'type' => 'date',
  );
}

Notice that the parameter by reference $data is never actually altered.