Add a message when adding Wordpress Category

I have a function hooked on created_term and I'm trying to add a message a return success or error message. Categories are created with Ajax, I tried some things but it's overwritting Wordpress error and causing bugs.

My code so far:

add_action( 'created_term', 'push_term', 20, 3);
function push_term( $term_id, $tt_id, $taxonomy ) { 
                $contentarray = array();

                $term = get_term_by( 'id', $term_id, $taxonomy);

                if(!empty($term->name)){ $contentarray['category_name'] = $term->name; }
                if(!empty($term->slug)){ $contentarray['category_slug'] = $term->slug; }
                if(!empty($term->description)){ $contentarray['category_desc'] = $term->description; }

                $category = $taxonomy.'_#'.$term_id;

                if(post_content($apikey, $websitekey, $category, $contentarray)){
                    if ( is_admin() && defined( 'DOING_AJAX' ) && DOING_AJAX )
                    {
                    }
                }else{
                    if ( is_admin() && defined( 'DOING_AJAX' ) && DOING_AJAX )
                    {
                    }
                }
    }

Thanks in advance, been trying to figure this out for a while...

via Chebli Mohamed