How do I get analytics for WebMCP tools on my site?

Why instrumentation matters

A browser-local WebMCP call may not create a separate server request. A site can send its own analytics event for it; Agent Tracking observes supported APIs when the snippet is installed in time. It does not capture raw argument values.

Install before tool registration

Load the snippet before supported tool registration so it can observe registrations and calls. Declarative forms require supported markup and browser behavior. Check the Tools view after an actual call rather than assuming complete coverage.

await navigator.modelContext.registerTool({
  name: "add_to_cart",
  description: "Add a product to the cart by SKU.",
  inputSchema: { type: "object", properties: { sku: { type: "string" }, qty: { type: "integer" } }, required: ["sku"] },
  execute: async ({ sku, qty }) => { /* your code */ },
});

The questions the Tools view answers

How many observed calls occurred per tool and day, their technical success or failure and duration. A registered tool with no observed calls may be unused, or its activity may be outside the instrumented context. Errors are safe classes rather than raw messages.

From calls to outcomes

A data-agent-goal marker records a browser attempt. A site-server outcome endpoint records a confirmed business event. Read both separately unless your own workflow links the specific call and receipt.

<button type="submit" data-agent-goal="order_placed">Place order</button>

In short