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

With no annotations, the description carries the full burden and does so well: it discloses the signing behavior, the exact payload shape ('shaped like a message.received: the text is at data.message.text'), the ~10 second wait window, the retry of a failed first attempt, and what the response contains including the exact payload sent. These are non-obvious traits an agent could not get from structured fields.

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?

One front-loaded sentence plus a short retry note and a closing sentence about the returned payload; every clause carries information. Slightly dense with nested parentheticals, which costs a little readability.

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?

For a single-parameter, no-output-schema tool, the description supplies everything an agent needs: what is sent, how it is signed, how long it blocks, retry semantics, and exactly what comes back. Nothing material is left to guess.

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?

There is one parameter, webhook_id, with 0% schema description coverage. The description implies it is the target of the test ('send ... to a webhook') but never explains its format or where to obtain it (e.g., from list_webhooks). The single obvious parameter keeps this from being a larger gap.

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?

The description states a specific verb and resource ('Send a webhook.test event to a webhook') and defines the outcome ('say whether it was delivered: the status the URL answered, or why it failed'). That is clearly distinguishable from update_webhook, create_webhook, and resend_webhook_delivery without opening any schema.

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 test-event framing implies the use case (verifying a webhook endpoint works), but there is no explicit when-to-use statement and no routing away from the nearest alternative, resend_webhook_delivery, which also triggers a delivery. Usage is inferable rather than stated.

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