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

Far exceeds what annotations provide: it discloses the exact event payload, the Fold-Signature header format with the HMAC construction over "t.body", the fact that a secret is returned, the per-order cap of 3, and both auth modes. Annotations flag this as a non-readOnly, openWorld, destructive, idempotent operation, and the description supplies the operational details an agent needs to call it safely.

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-loaded with the capability and precondition, then structured into labeled Payload and Header segments. Dense but nearly every clause carries information; the trailing auth-and-limit sentence is slightly compressed but not wasteful.

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 compensates by describing both the webhook payload and the fact that a signing secret is returned. Remaining gaps are minor: it does not say how to remove a subscription or what happens when re-registering the same URL.

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?

Adds meaning beyond the 67%-covered schema: email is explained as the address used when scheduling and only needed when there is no connected account, and webhookUrl's https requirement plus the per-order limit of 3 clarify the registration constraints. orderCode is left implicit (it scopes the subscription to one order), but the surrounding text makes that clear.

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 and resource — registers an https URL that Fold POSTs to on every status change of one order — and enumerates the triggering events (picked up, washing, out for delivery, delivered). An agent can immediately tell this is a webhook subscription tool, not a notification-preference or tracking tool.

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?

Gives a clear precondition ("For agents that can receive webhooks"), two valid authentication paths (connected account, or order code + scheduling email), and a hard constraint (max 3 per order). It does not, however, distinguish itself from the obvious alternative update_notification_preferences, which an agent could confuse it with for notification setup.

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