Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=false, idempotentHint=false, and openWorldHint=true; the description adds the non-obvious detail that delivery happens "off the request" (asynchronous, the call returns before the event lands) and that verification is a few seconds later in the audit-log/deliveries view. It does not say what the call returns or what happens if the target URL is unreachable, which keeps it below a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences with no filler; the async behavior is front-loaded and the UI breadcrumb is compact. The opening fragment ("On one site of the account, named in site.") is slightly awkward but does put scope first.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description usefully explains where the observable result appears instead of what is returned, and annotations cover the safety/idempotency profile. The only gap is failure behavior (bad URL, unknown webhook id), which is not addressed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so both parameters are already documented. The description adds only the framing that the site scopes the account and that the webhook is the one whose event is sampled — useful but marginal beyond the schema, so baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

"Sends a sample of the webhook's event to its URL, once" is a specific verb-plus-resource statement that cannot be confused with create_webhook, update_webhook, delete_webhook, or list_webhooks. The scope (one site of the account) is stated in the first clause.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The purpose strongly implies the use case (verify a webhook actually delivers), and the pointer to Settings › Webhooks, Deliveries tells the agent where to confirm the outcome. However, there is no explicit when-not-to-use guidance and no mention of alternatives such as inspecting prior deliveries via list_webhooks or other diagnostics.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.