This page has no agent host. It installs the package's fake host, registers two tools (a fast text tool and a slow one returning an image), fires ten calls with random pauses, and opens the panel. What you should see, bottom left: a row per tool with calls, p50, p95, and the last result size, and under it the split: schemas (descriptor bytes the host ships every conversation), tools (execute time), payloads (result bytes and estimated tokens), and host gaps (the pauses, standing in for model think time).
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Then in DevTools: __webmcpPerf.help().