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

Annotations already indicate this is a destructive, write operation, and the description adds behavioral context beyond that: it warns not to invent or retry with different identities, notes that Gondola derives traveler ID and a stable booking request ID, and explicitly says never to provide card numbers or security codes. The idempotency guidance about uncertain outcomes is especially valuable.

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 dense but every sentence carries operational value: confirmation precondition, required ID sources, identity handling, and uncertainty handling. The most critical constraint ('only after the traveler explicitly confirms') is front-loaded, and nothing is redundant.

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 complex, destructive mutation with 9 required parameters and nested objects, the description covers prerequisites, source of every derived ID, confirmation requirements, and failure-handling guidance. The output schema exists, so return-value explanation is unnecessary; the description is complete for correct invocation.

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, but the description adds meaningful semantics by tying each ID to its source (prepare_flight_booking, get_payment_methods) and emphasizing exactness of total, currency, quote, and consent version. It also conveys required behavior for traveler identity even though the schema already names the fields.

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 names the specific action ('Book a prepared flight') and the precise precondition: after traveler confirmation of the exact quote. It clearly differentiates from prepare_flight_booking by requiring handoff_id, quote_id, and a saved payment_id, and from cancellation tools by focusing on completing a booking mutation.

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 explicitly states when to call this tool (only after explicit traveler confirmation), which prerequisite tools produce the required IDs (prepare_flight_booking, get_payment_methods), and what to do instead when the outcome is uncertain (retrieve booking state rather than repeating the mutation). This is strong, unambiguous guidance.

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