Set up description meta automatically

You can use first few lines of post content and add these to meta description tags to website head section automatically.

Here is how you do that.

// add meta description tag
function wcs_add_meta_description_tag() {
    global $post;
    if ( is_single() ) {
        $meta = strip_tags( $post->post_content );
        $meta = strip_shortcodes( $post->post_content );
        $meta = str_replace( array("\n", "\r", "\t"), ' ', $meta );
        $meta = mb_substr( $meta, 0, 125, 'utf8' );
        echo '<meta name="description" content="' . $meta . '" />' . "\n";
    }
}
add_action( 'wp_head', 'wcs_add_meta_description_tag' , 2 );

Ofcourse You can change this code to use post excerpt for meta description tag.