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

Goes well beyond the annotations (write, non-idempotent, non-destructive) by disclosing the one-time signing secret, the required permission level, the HMAC-SHA256 signature scheme and headers, the retry schedule (five retries over ~15 hours), and automatic disabling of persistently failing webhooks. These are exactly the behavioral traits an agent cannot infer 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?

Front-loads the use case before diving into mechanics, and every sentence carries actionable content (secret handling, signature verification, retry/dedup semantics). It is dense and long, but nothing reads as filler; the length is justified by the integration details a caller needs.

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 carries the return-value burden and does so: it explains the one-time secret in the result, the delivery payload shape, and failure/retry behavior. Nothing essential for calling or consuming this webhook registration correctly is missing.

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 the schema already documents url, events, and workspace_id, and the baseline is 3. The description mentions subscribed events and the site.viewed payload fields but adds no syntax or format detail for the parameters themselves beyond what the schema provides.

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?

States a specific verb (registers) and resource (an https endpoint for webhook deliveries) plus the exact triggering condition (user wants their system told when someone opens a site). An agent can distinguish it from list_webhooks and delete_webhook 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?

'Use when the user wants their own system told when someone opens a site in this workspace' gives a clear when-to-use context, and the owners/admins-only restriction narrows applicability. It stops short of explicitly naming the sibling alternatives (list_webhooks, delete_webhook) it is mutually exclusive with.

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