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

With no annotations, the description carries the full burden and does disclose the key behavioral traits: automatic refund within the free window, a `bloqueado: true` response signal for out-of-window/non-refundable fares, and the manual escalation path. It leaves out token/auth expectations and whether a successful cancellation is reversible, which keeps it from a 5.

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?

Front-loaded with the action and outcomes, and every sentence adds operational value (including the no-retry warning). Slightly long-winded in the escalation clause, but 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?

No output schema exists, yet the description usefully documents the response shape via the `bloqueado: true` flag and what to do next, which is exactly the kind of return-value detail an agent needs. The main remaining gap is the unexplained `token`/`order_id` semantics.

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% across 3 parameters, so the description must compensate. It explains only `language` (values 'en'/'pt'/'es' for error messages); `token` and `order_id` receive no explanation beyond their self-evident names. Partial compensation, so a middling 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?

States a specific verb and resource ('Cancela uma reserva') and immediately characterizes the two possible outcomes (auto-refund vs. blocked). No sibling tool performs cancellation, and the description makes that unambiguous.

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 routes behavior: cancel-and-refund inside the free window, and for the blocked/non-refundable case it instructs the agent to escalate to a human email and explicitly not retry ('NÃO insista tentando de novo'). That is a clear when-to-use / when-not-to-retry rule, not merely implied.

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