WEB DEVELOPMENT / JetBrains
Modern Web Guidance
Routes HTML, CSS and client-side JavaScript work through a searchable corpus of Chrome-authored best-practice guides — container queries, dialogs and popovers, view transitions, scroll-driven animation, forms and autofill, image priority — with Baseline browser-support policy rules for fallbacks.
“Search tool for modern web development best practices. MANDATORY: Execute FIRST for all HTML/CSS and clientside JS tasks.”
01 / THE REASONING
Why this made the selection.
- Turns modern-CSS and forms guidance into a queryable corpus instead of a fixed checklist: the agent searches an action-oriented phrase, gets scored matches with token counts, then retrieves only the guide it needs.
- Encodes a browser-support policy discipline — Baseline widely-available features need no fallback, everything else must follow the guide's fallback recommendation unless the project declares its own policy — which is the decision agents most often get wrong.
- The mirror bundles the guide corpus in twelve category directories (css, css-layout, forms, html, performance, security, accessibility, passkeys, privacy, user-experience, webmcp, built-in-ai), so the material travels with the SKILL.md and not only through the npm search tool.
02 / THE REVIEW RECORD
What we actually inspected.
Source review has boundaries.
A clear record is more useful than a “safe” badge.
Material inspected
- modern-web-guidance/SKILL.md (JetBrains mirror, complete, 119 lines)
- modern-web-guidance/guides directory listing (12 category directories)
- modern-web-guidance/LICENSE (skill-local, Apache-2.0)
- upstream GoogleChrome/modern-web-guidance skill definition and LICENSE
- JetBrains/skills README mirror policy
Our findings
- The search-retrieve workflow is concrete: an action-oriented query returns scored matches with id, category, featuresUsed and tokenCount, retrieve accepts multiple ids, and a list fallback exists for vague queries.
- The browser-support section converts Baseline status into an explicit fallback policy with worked policy examples (Safari 17.4+, no-polyfill, feature-detected newly-available) and pushes the project to write its policy down.
- The mirror's skill-local LICENSE is Apache-2.0, matching the upstream GoogleChrome repository, and the front matter credits that upstream with a pinned skill version 0.0.166.
Not established by this review
- No npx search or retrieve command was executed; the workflow was read, not run.
- No guide was applied to a live layout or forms task.
The review applies to the material and revision named here. A newer upstream release can change its behavior.
03 / PUT IT TO WORK
Add a skill to your workflow.
DOCUMENTED COMMAND
npx skills add JetBrains/skills/modern-web-guidance --skill modern-web-guidanceRun in your terminal to choose your AI tools, project or global scope, and installation method. This short command follows the current upstream version; the review covers the revision shown above.
Optional: install the reviewed revision
Keeps the original source and installer version where recorded, while leaving your AI tools and installation scope for you to choose.
npx skills add https://github.com/JetBrains/skills/tree/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/modern-web-guidance --skill modern-web-guidance- Install the complete skill directory; the bundled guides must travel with the SKILL.md or offline use degrades to the npx tool only.
- Point the agent at the front-end feature being built and let it search first; keep the runtime Node/npm and network prerequisite in mind.
Before you start
- Node.js/npm for the installer and for the search tool
- An agent that supports the Agent Skills format
- Network access when using the npx search workflow
04 / FOLLOW THE EVIDENCE
The source trail.
Our notes are separate from the original resource.
Check upstream before adopting a new version.
https://github.com/JetBrains/skills/blob/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/modern-web-guidance/SKILL.md
Supports: summary, upstreamDescription, whySelected, bestFor, limitations, review, access
https://github.com/JetBrains/skills/tree/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/modern-web-guidance/guides
Supports: review, whySelected
https://github.com/JetBrains/skills/blob/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/modern-web-guidance/LICENSE
Supports: license
https://github.com/GoogleChrome/modern-web-guidance/blob/a97286845f2baba38988f9e5fe2b2a1351021e50/skills/modern-web-guidance/SKILL.md
Supports: review, limitations
https://github.com/JetBrains/skills/blob/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/README.md
Supports: review, install
https://github.com/vercel-labs/skills/blob/7407f3893ad4dceab546ac002c3ef806e4000c73/README.md
Supports: install