Agent Skills: html-tools

Build single-file HTML tools — self-contained HTML+JS+CSS applications that solve a specific problem without a build step. Use this skill whenever the user asks to build a utility, converter, viewer, debugger, or any small interactive web tool. Also trigger when the user says "build me a tool that...", "make a quick app for...", "I need a single-file HTML page that...", or wants to create something that could be hosted as a static file. This skill is specifically for practical, utility-focused tools (not landing pages, portfolios, or marketing sites — use frontend-design for those).