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

With no annotations, the description reveals important behaviors: scope requirement, tenant constraint, and idempotency. It does not mention side effects like notifications, but the core effect is clear.

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 a single concise sentence that packs essential information: prerequisites, action, and a key behavioral trait (idempotency). No redundant words.

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?

The description adequately covers prerequisites and idempotency, but lacks mention of the return value or confirmation of success/failure. Given the tool's simplicity and no output schema, this is a minor gap.

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 schema covers the single parameter with a description ('Reservation UUID to cancel.'). The description adds no additional semantics beyond the schema, so baseline 3 is appropriate.

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 'Cancel a reservation by UUID', specifying the action and the identifier. This distinguishes it from sibling tools like 'create_reservation' or 'list_reservations'.

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 explicitly requires the reservations:write scope and notes the reservation must belong to the key tenant. It also mentions idempotency for already-cancelled reservations. While it doesn't explicitly exclude other tools, the context is sufficient for correct usage.

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