WebMCP agent-facing probe

Answers "does the agent discover and call these tools, and what can it see?" — which page.html does not test. Everything renders on-page; no console required.

Environment

Registered tools (via getTools)

…

Canaries (ask the agent which it can see)

DOM text
SVG text
Canvas
aria-hidden
title attr	hover target
memory only	never rendered — control

Pending approval queue

none

Invocation log

waiting for tool calls…

Below the fold

Offscreen canary:

build 2026-08-26T20:51:53.993Z · origin-trial tokens: 1