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

Annotations already establish readOnly, idempotent, and closed-world behaviour, so the safety profile is covered. The description adds genuinely useful context beyond that: the required bearer credential format (Authorization: Bearer cmt_...) and how an account holder obtains one. It does not mention rate limits or failure modes, but the auth disclosure is substantial added value.

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, front-loaded with the outcome the caller cares about. The auth sentence carries real value, though the included phone number for obtaining a key is the least essential element.

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 an output schema present, the description does not need to enumerate return values (it does so anyway, which is a bonus), and it covers the one non-obvious operational requirement, authentication. For a single-parameter read tool this is essentially complete; only explicit sibling routing and error behaviour are 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 the single order_number parameter, including that it accepts either a Comet tracking number or a request_id from book_delivery. The description adds nothing about parameters, so the 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?

Starts with a specific verb+resource: it reports where an order is on the account, and enumerates the concrete states returned (booked, picked up, delivered with signer/time, cancelled). It implicitly distinguishes itself from the plural sibling recent_orders by being a single-order lookup, but never names or contrasts with any sibling explicitly.

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?

Usage is implied rather than stated: an agent can infer this is the tool to call when it needs the current state of one known order. There is no guidance on when to prefer recent_orders or book_delivery, and no stated prerequisites or error conditions (e.g. unknown order numbers).

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