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

Annotations declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false; the description explains exactly why the read is not side-effect free — for flights it opens 'a pending airline cancellation that expires unused' — and reassures that 'No money moves.' It also discloses the cancel-permission requirement for full-refund confirmations, context the annotations cannot convey.

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?

Roughly four sentences, purpose front-loaded, then next-step, then a labeled 'Effects:' clause. Every sentence carries distinct information — scope, follow-up path, and side-effect profile — with no repetition or 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?

With no output schema, the description still tells the agent what the quote returns (refund amount, whether it is the full amount paid, and the confirmation path). Combined with the side-effect disclosure, an agent has everything needed to call it correctly and act on the result.

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%, and the schema already documents both booking_ref (format bkg_) and request_key (idempotency/reuse semantics). The description adds no parameter-level detail, which is acceptable at full coverage; baseline 3.

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 first sentence names a specific action (ask the supplier what cancelling one booking would refund) and the resource (a single booking's cancellation terms). It clearly distinguishes itself from anywayr_confirm_cancellation by stating it 'Cancels nothing.' An agent can route correctly without opening the schema.

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?

The description establishes the flow context ('the next step: confirm in chat... or a link') and an operating rule ('tell the traveller the refund before any confirmation'). It stops short of explicitly naming anywayr_confirm_cancellation as the follow-up call, but the sequencing is clear enough that the agent knows when this tool fits.

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