By default, Goodreads sorts the to read shelf by least recently added. This reverses that.

goodreads-sort-to-read-by-date-added.js

// ==UserScript==
// @name Goodreads: Sort To Read by most recently added.
// @namespace Violentmonkey Scripts
// @match https://www.goodreads.com/*
// @downloadURL
// @grant none
// ==/UserScript==

const getLinksToUpdate = () => {
  // Get all links to the to-read shelf that don't specify a sort order.
  return document.querySelectorAll('a[href*="/review/list/"][href*="shelf=to-read"]:not([href*="sort="])');
}

const updateLinks = () => {
  for (const link of getLinksToUpdate()) {
    link.setAttribute('href', link.href + "&sort=date_added")
  }
}

updateLinks();