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

Annotations already declare it is a non-destructive, open-world mutation. The description adds real behavioral context beyond that: the provider/team is retained by default, fees are configured server-side and should be checked, and there is a per-call confirmation default plus an external-recipient warning. Auth needs are also stated. It stops short of describing failure modes or partial-success behavior.

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 first two sentences are near-duplicates ('Move a booking to a new date and arrival time' vs 'Moves one booking to a new date and arrival time and returns the updated booking'), which wastes space. The remaining clauses are front-loaded reasonably well but the framing boilerplate ('BookingKoala:', 'Needs the user's Cotlet API key') dilutes focus.

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, the description covers the essentials: what changes, what is preserved, the fee caveat, confirmation requirements, and credential needs. An agent could invoke it correctly. Minor gaps remain around error/edge handling, but nothing critical 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?

Schema description coverage is 100%, so all three parameters are already documented. The description slightly reinforces keep_provider semantics ('stays unless keep_provider is false') and the arrival concept, but adds little meaning beyond the schema. 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 states a specific verb and resource ('Move a booking to a new date and arrival time') and notes the return value ('returns the updated booking'). It is unambiguous, but it does not explicitly differentiate itself from the other bookingkoala siblings (e.g. cancel_booking, create_booking) beyond the verb itself.

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 gives context — check rescheduling fees before bulk moves, confirm each call, confirm with the user before each call since it 'reaches other people' — which implies usage conditions. However, it never states when to use this versus alternatives, and no exclusion guidance is offered.

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