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

The description adds meaningful behavioral context beyond the annotations: cancellation is free of charge, must happen before pickup, requires customer_confirmed=true after explicit customer confirmation, and cannot be undone. These details are not present in the annotations or schema and materially shape how and when the tool should be used.

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?

The description is compact and front-loaded: the first sentence states the core behavior and key constraints, followed by a concise list of prerequisites and the irreversible nature of the action. There is no redundant or filler language.

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?

Given the annotations, output schema presence, and the relatively simple cancellation semantics, the description covers all critical operational aspects: what happens, when it can happen, prerequisites, costs, and irreversibility. No essential information for invoking the tool 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?

The description reinforces which parameters are essential and adds the crucial semantic that customer_confirmed must be set to true only after the customer explicitly confirms. Schema descriptions already cover access_code, idempotency_key, and booking_reference, but the optional 'reason' parameter is not explained. The description partially compensates for the coverage gap by emphasizing the required confirmation flow.

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 clearly states the action ('Cancels a booking') and identifies the specific resource. The addition of 'free of charge, any time before the pickup' distinguishes this cancellation operation from the sibling update/get/hold tools. An agent can immediately tell this tool is for canceling, not modifying or retrieving.

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 description gives explicit usage context: cancellation is possible any time before pickup and requires customer confirmation before the flag is set true. It does not explicitly name alternative tools or list exclusions, but since no sibling is a cancellation tool, the primary use case is unambiguous.

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