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

Annotations already declare readOnly, idempotent and non-destructive, so safety is covered; the description goes further by disclosing the shape of the answer, including the PayPay payment link, amount and deadline when waiting for payment. It does not mention token expiry, polling limits, or how long a status remains queryable, which are the remaining behavioral gaps.

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?

Two sentences, front-loaded with the outcome and followed by the input dependency; there is little waste. The opening clause 'Where a reservation ... stands' is slightly indirect versus simply saying it returns the reservation's status.

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 burden of describing returns and does so by enumerating statuses and payment details, which is the key information for an agent deciding what to do next. It omits renewal/expiry behavior of status_token and expected response timing, so it is strong but not exhaustive.

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 coverage is 100% and the schema fields already say both values come from confirm_reservation, so the description's restatement adds no new syntax or constraints. Baseline 3 applies because the schema does the heavy lifting.

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 names a specific verb+resource (read the state of a reservation) and anchors it to the sibling that creates it, confirm_reservation. It enumerates the possible states (being reserved, awaiting payment, paid, not taken, cancelled, lapsed), so an agent knows exactly what it will learn and can distinguish it from start_reservation or check_trail_availability.

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?

It states the prerequisite clearly: the tool operates only on a reservation made with confirm_reservation and requires order_id and status_token from that call. There is no explicit when-not guidance or named alternative for other reservation queries, which keeps it just short of a 5.

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