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

Beyond the destructiveHint annotation, the description discloses that an allowed cancellation has no undo, that unsafe refund/restore cancellations are refused, and that reusing the idempotency_key makes retries safe. This gives the agent critical behavioral expectations not available from annotations or the schema alone.

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 three tight sentences with no filler. It front-loads the primary action and confirmation requirement, then covers retry safety and refusal constraints. Every sentence contributes either to correct invocation or to setting the correct risk expectation.

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 tool's destructive nature, the description covers the essential operational guardrails: user confirmation, grant authorization, idempotent retries, refusal conditions, and irreversibility. An output schema exists, so return-value documentation is not the description's responsibility. The description is complete enough for an agent to use the tool safely and correctly.

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 80%, with grant, booking_ref, tenant, and idempotency_key already well documented in the schema. The description adds contextual emphasis on the grant requirement and idempotency safety, but it does not materially expand parameter meaning beyond what the schema already provides. A baseline 3 is appropriate given the high schema coverage.

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 states a specific verb and resource: 'Cancels one grant-authorized booking'. The phrase 'after explicit user confirmation' and the cancellation-specific constraints clearly distinguish this tool from siblings like reschedule_booking or get_booking_status. The purpose is unambiguous and immediately usable by an agent.

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 provides clear when-to-use context: cancellation only after explicit user confirmation, and only for grant-authorized bookings. It also states a when-not condition by describing cancellations Kirah refuses (those that refund a charged deposit or restore a paid plan session). It does not explicitly name alternatives such as reschedule_booking, but the cancellation scope is clear enough for correct tool selection.

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