diff --git src/wp-includes/taxonomy.php src/wp-includes/taxonomy.php
index f361c3b..8e68567 100644
--- src/wp-includes/taxonomy.php
+++ src/wp-includes/taxonomy.php
@@ -2000,13 +2000,12 @@ function sanitize_term_field($field, $value, $term_id, $taxonomy, $context) {
  *
  * Default $args is 'hide_empty' which can be 'hide_empty=true' or array('hide_empty' => true).
  *
- * @todo Document $args as a hash notation.
- *
  * @since 2.3.0
  *
- * @param string       $taxonomy Taxonomy name
- * @param array|string $args     Overwrite defaults. See get_terms()
- * @return array|int|WP_Error How many terms are in $taxonomy. WP_Error if $taxonomy does not exist.
+ * @param string       $taxonomy Taxonomy name.
+ * @param array|string $args     Optional. Array of arguments that get passed to {@see 'get_terms'}.
+ *                               Default empty array.
+ * @return array|int|WP_Error Number of terms in that taxonomy or WP_Error if the taxonomy does not exist.
  */
 function wp_count_terms( $taxonomy, $args = array() ) {
 	$defaults = array('hide_empty' => false);