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

Annotations only declare the mutation/idempotency profile, but the description carries much more: nothing is charged by any tool, the booking exists only after payment on Nuitee's form, booking_secret is shown once, price_changed flags repricing, and idempotency_key makes retries safe. These are real behavioral traits beyond the structured hints.

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-loads the core action and return values, then moves to guest-facing instructions, with no filler sentences. It is dense and slightly long, but each clause (repricing, cancellation terms, API key) carries actionable information.

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 14-parameter mutation with no output schema, the description adequately explains what is returned (booking_id, booking_secret, total, price_changed, cancellation terms, pay_url) and the auth prerequisite, so an agent has everything needed to call it 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%, so the schema already documents dates, nationality defaults, currency, and idempotency semantics. The description largely restates the critical constraints (guest name matching the ID, phone with country code, sending an idempotency key) rather than adding new format or edge-case detail, so 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?

States a specific verb and resource ('Holds one room ... with the partner for the named guest') and names where the offer_id comes from (search_hotels, get_hotel), which cleanly separates it from those exploration siblings. An agent can identify this as the committing step of the booking flow 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?

Gives clear sequencing context — this follows search_hotels/get_hotel, and the guest pays on pay_url rather than through the tool — plus a concrete fallback (request_api_key) when the connection lacks a key. It never states an explicit when-not or a named alternative for the booking step (e.g., vs cancel_booking), so it stops short of 5.

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