Flickr batch title and description setter ... just run it in browser's console

flickr_title_and_description.js

var title = "Photo title";
var description = "Photo description";
document.querySelectorAll('.together_description').forEach(elm => { elm.value = description; elm.dispatchEvent(new Event("change")) }); 
document.querySelectorAll('.together_title').forEach(elm => { elm.value = title; elm.dispatchEvent(new Event("change")) });  
document.getElementById("batch_edit_together_form_save_button").scrollIntoView();