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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the agent knows this is an irreversible-looking mutation before reading the text. The description adds only that the time slot is released, but says nothing about required ownership or permissions, whether the cancellation can be undone, or what happens to attendees or notifications. With annotations covering the safety profile, this modest addition justifies a 3.

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?

One short sentence, front-loaded with the action and the resulting effect, with no filler. It is efficient rather than bloated, though its extreme brevity leaves the gaps noted in other dimensions.

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?

For a destructive mutation with an undocumented identifier and no output schema, the definition should say what a booking is in this system, what id to supply, and what the cancellation affects. None of that is present, so an agent cannot confirm it is targeting the right record type.

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 0% for the single required parameter "id", and the description never clarifies which entity the id refers to (a booking, appointment, or event instance) or its format. The description therefore fails to compensate for the undocumented parameter.

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 gives a specific verb and resource ("Annuler une réservation") plus the side effect ("libérer le créneau"), which is more than a restatement of the name. It does not, however, distinguish this from adjacent cancel tools such as cancel_subscription or cancel_site_project_job, and it is written in French while the name, title and annotations are English.

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?

There is no statement of when to call this versus another cancel tool, no prerequisites, and no warning about irreversibility. The only usage-adjacent information is the implied consequence of freeing the slot.

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