Added short argument explanation

application/helpers/env_helper.php

@@ -20,8 +20,8 @@ if ( ! function_exists('env'))
      *
      * $debug = env('debug', FALSE);
      *
-     * @param string $key
-     * @param mixed $default
+     * @param string $key Environment key. 
+     * @param mixed $default Default value in case the requested variable has no value.
      *
      * @return mixed
      */

application/helpers/session_helper.php

@@ -26,8 +26,8 @@ if ( ! function_exists('session'))
      *
      * session(['logged_in' => FALSE]);
      *
-     * @param array|string $key
-     * @param mixed $default
+     * @param array|string $key Session item key. 
+     * @param mixed $default Default value in case the requested session item has no value.
      *
      * @return mixed|NULL Returns the requested value or NULL if you assign a new session value.
      *

application/helpers/setting_helper.php

@@ -26,8 +26,8 @@ if ( ! function_exists('setting'))
      *
      * setting(['company_name' => 'ACME Inc']);
      *
-     * @param array|string $key
-     * @param mixed $default
+     * @param array|string $key Setting key. 
+     * @param mixed $default Default value in case the requested setting has no value.
      *
      * @return mixed|NULL Returns the requested value or NULL if you assign a new setting value. 
      *