How to describe needed information for a method

gistfile1.php

<?php
class TestAction implements GenericAction
    /**
     * How would I describe that this method required the 'test'-parameter to be set?
     *
     * It shouldn't be @param as it's not a parameter to the method. An inline/embedded PHPDoc-comment 
     * wouldn't work as there's nothing I could add it to.
     *
     * I would have expected something like @requires or @expects to define that like so:
     *
     * @expects string $this->getRequest()->getParam('test) The give REQUEST-parameter 'test'
     * 
     * @return mixed
     */
    public function testAction()
    {
        $test = $this->getRequest()->getParam('test');
    
        return $test;
    }
}