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

The description discloses side effects not captured by annotations: it notifies the attendee, removes from connected calendars, and is irreversible. The warning that cancelling one occurrence of grouped/recurring bookings can affect several meetings adds behavioral nuance beyond the destructiveHint annotation. No contradiction with annotations; idempotentHint and destructiveHint are consistent.

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 sentences, each carrying essential information: action and effects, ID provenance, and caution for grouped/recurring bookings. It is front-loaded with the core purpose and contains no filler.

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 single-parameter cancellation tool with no output schema, the description covers purpose, side effects, irreversibility, ID source, and a critical edge case. The presence of annotations further covers safety profile, and nothing an agent needs to call 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 schema already describes booking_id as 'Exact booking_id from list_upcoming_bookings' with 100% coverage, so baseline is 3. The description reinforces this and adds 'never a guessed or reconstructed one', and explains that a booking_id may represent grouped/recurring bookings affecting multiple meetings, adding semantic nuance beyond the schema.

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 opens with 'Cancel a confirmed booking', a specific verb and resource. It distinguishes from siblings by focusing on the cancellation action, contrasting with the list_* tools and create_booking. Mentioning attendee notification and calendar removal further clarifies its unique scope.

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 instructs using an exact booking_id from list_upcoming_bookings, never a guessed or reconstructed one, providing a clear source and constraint. The warning to confirm which meetings the person means for grouped/recurring bookings gives practical usage guidance. However, it doesn't explicitly contrast with alternatives beyond the ID source, so not a full 5.

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