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

Adds substantial behavior beyond annotations: calendar event update, provider attendee notification, payment carry-over, 409 change_too_late error, and the prohibition on moving pending_approval requests. Annotations only confirm it is a non-destructive write.

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?

Five sentences, each carrying a different constraint or behavior. Front-loaded with the core action and well-structured, though slightly dense with edge cases.

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?

Covers preconditions, side effects, error condition, and the pending_approval exclusion. No output schema exists, but the return is implied by success behavior; minor gap on whether the response returns updated booking details.

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 coverage is 100%, so the baseline is 3. The description adds value by telling where valid `start` values come from (get_available_slots) and that both `bookingId` and `token` are required to fetch them, which complements the schema's formatting detail.

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?

States a specific verb (moves) and resource (confirmed booking to `start`) with the scope constraint (same hosts). Distinguishes from siblings by implying cancel_booking_as_invitee is the alternative for non-movable requests.

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?

Explicitly names get_available_slots as the source of valid times, describes the precondition (before changeableUntil), and gives an alternative workflow for pending_approval requests: cancel and re-request. This routes the agent without ambiguity.

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