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

Annotations already flag idempotentHint=true and destructiveHint=false, but the description adds real context: retrying with the same idempotency_key never creates a second booking, the call blocks the day, and it returns a booking reference plus customer access code. It doesn't discuss permissions, failure modes, or what happens when a quote_id has expired.

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?

Four sentences, each earning its place: what it does, the precondition, the required inputs and idempotency guarantee, and the return values. The precondition is front-loaded ahead of parameter detail.

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 25-parameter mutation tool with an output schema available, the description covers the essential decision gate and the idempotency contract. What is missing is guidance on stale/invalid quote_ids and the fact that stops/child_seats must be empty, though the schema itself flags those.

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 coverage is 56% across 25 parameters, so the schema does much of the work. The description reinforces four required parameters (quote_id, customer_confirmed, accepted_terms, idempotency_key) and adds the idempotency retry semantics, but says nothing about the many address, flight, or luggage parameters the agent must still fill.

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 states a specific verb and resource ('Creates a REAL, CONFIRMED booking in RIED.TAXI's booking system and blocks the day'), and the 'CONFIRMED' plus 'blocks the day' framing distinguishes it from ried_taxi_hold_booking, which only reserves. An agent can identify the operation 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?

It gives an explicit gating condition – 'Only call after the customer has seen the complete trip and price and explicitly said yes' – which implies the get_quote → create sequence. It does not name hold_booking or update_booking as alternatives or state when to prefer them, so it stops just short of full routing guidance.

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