Agent skill
Let your coding agent add WebMCP for you
adding-webmcp-tools is a free skill for AI coding agents. It picks which of your site's actions should become tools, writes them to match the current WebMCP draft, marks the risky ones, and then checks the live site.
What it does
- Chooses tools from what visitors come to do: search, look up, book, add to cart. Leaves out logins and payments.
- Writes form tools with the four attributes Chrome documents, or script tools with
document.modelContext.registerTool, an abort signal and a caught promise. - Sets
readOnlyHint,consequentialHintanduntrustedContentHintwhere they belong. - Replaces old code:
navigator.modelContext,provideContext,unregisterTool. - Tells you how to test in Chrome, then runs the same free check as our checker on your live site.
Install
| Agent | How |
|---|---|
| Claude Code | /plugin marketplace add Convertlyft/skills then /plugin install convertlyft@convertlyft |
| Codex | codex plugin marketplace add Convertlyft/skills then codex plugin add convertlyft@convertlyft |
| Cursor | Plugins & MCPs → Add Marketplace → Import from Repo: Convertlyft/skills |
| Other agents with skills | npx skills add Convertlyft/skills |
Then ask your agent: “Add WebMCP tools to this site.” The skill and the free check need no account. The plugin also adds Convertlyft's other skills.
Written from the draft, not from memory
WebMCP changed a lot in 2026: the API moved from navigator to document, three methods were removed, and the form attributes left the spec. Most code online is out of date. The skill is pinned to the draft of 20 October 2026 and is updated when the spec tracker records a change.