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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds real value beyond that by stating this is a post-payment verification step and that BOTH booking id and guest email are mandatory, implying a lookup that fails without matching credentials. It does not describe behavior when the email does not match the booking.

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?

Three tight sentences: what it verifies first, prerequisites second, timing third. No filler, and the most decision-relevant content (verb + returned fields) is front-loaded.

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 only two fully documented parameters, an explicit read-only annotation, and no output schema, the description supplies everything needed: it enumerates the returned fields in lieu of an output schema and pins the call to the correct point in the booking workflow.

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 the baseline is 3; the description goes further by explaining where the values originate (the guest's confirmation) and emphasizing that both are jointly required, which matters for a lookup keyed on a pair rather than a single id.

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 (Verify) and resource (a completed booking) and enumerates exactly what is retrieved: confirmation status, hotel confirmation code, stay and price. It also names the sibling it follows (prepare_booking), so an agent can place it in the booking flow without opening a 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?

Gives an explicit trigger and sequencing: 'Use after the human pays via a prepare_booking link,' plus the prerequisite that both identifiers come from the guest's confirmation. It lacks an explicit when-not or a named alternative for other booking states (e.g. pre-payment lookups), which keeps it short of a 5.

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