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

Annotations already declare this is not read-only, is open-world, and is not destructive. The description adds useful context beyond them: owner-only access and that the customer is notified of a new time, plus the implication that a start change and person change can happen together. It does not clarify what happens to the previous assignment or whether the operation is atomic/reversible.

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 two short sentences and front-loads the access requirement. The phrasing 'A new start, a new person, or both, in one swap' and 'The customer hears about a new time' is compact but somewhat colloquial and less precise than it could be.

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 mutation tool with no output schema and zero schema description coverage across three parameters, the description is thin. It covers authentication and a notification side effect, but leaves critical gaps around parameter meaning, target identification, and how it differs from sibling booking-change tools.

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%, so the description must carry parameter meaning. It loosely maps 'new start' to start and 'new person' to who, but does not define whether 'who' is a customer or staff member, does not mention the required booking_id, and gives no format or constraint details.

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 implies changing a booking's start time, assigned person, or both, but does not explicitly say it moves the booking or name the booking_id as the target. It also does not distinguish this from a sibling like reschedule_booking, so an agent must infer the difference from the name and title.

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 states an access condition (owners only, sign-in required), which is useful. However, it gives no guidance on when to use this instead of reschedule_booking, add_booking, or update_booking_rules, and no exclusions or prerequisites beyond sign-in.

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