The article introduces Modern Web Guidance, a set of skills that updates coding agents with the latest web best practices, steering them away from legacy patterns and towards modern web platform solutions. Developed by Google Chrome, Microsoft Edge, Mozilla Firefox, and MDN teams, along with the web development community, Modern Web Guidance helps coding agents generate efficient, production-ready code by leveraging native web platform capabilities, rather than relying on outdated JavaScript patterns. This is particularly important as many coding agents default to older patterns due to legacy code in their training data, resulting in bloated JavaScript code that can be replaced with high-performance web platform solutions.