PHP, WordPress, make nice content to description tag

description-tag.php

/**
 * Put some nice content into a description meta tag
 *
 * Usage:
 * <meta name="description" content="<?php echo ud_site_desc(); ?>">
 *
 * @return string 200 characters long descrption tag
 */
function ud_site_desc()
{
    global $post;
    if (is_single() || is_page()) {
        // On a single post and pages get first 200 characters
        // from the content
        $args = array(
            'p' => $post->ID,
            'post_type' => get_post_type()
        );
        $custom_posts = get_posts($args)[0]->post_content;
        $custom_posts = strip_shortcodes($custom_posts);
        $custom_posts = strip_tags($custom_posts);
        $custom_posts = trim($custom_posts);
        $custom_posts = str_truncater($custom_posts, 200);
        return $custom_posts;
    } else {
        // Otherwise get the site description
        return get_bloginfo('description');
    }
}