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

Annotations already declare readOnlyHint=true, openWorldHint=false, idempotentHint=true, destructiveHint=false. The description adds behavioral context beyond these: fare is set by the taxi company and shown before ordering, services grow city by city, and the crucial instruction to always provide the URL as a clickable link. This adds value without contradicting the annotations.

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 longer than average but necessary to cover three distinct services. It is structured with quoted service names and a critical final instruction, front-loading the core purpose. Every sentence earns its place, though it could be slightly tightened without losing 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?

Given the tool has 11 parameters and an output schema, the description explains the main flows and the crucial link-display rule. It doesn't detail every parameter, but the schema covers the rest. It provides enough context for an agent to invoke it correctly across the three services.

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 73%, so the description supplements it. It clarifies which parameters apply to which service (e.g., origin, destination, passengers, luggage, and when are taxi-specific; pickup_date and return_date are car rental; shipment_scope for shipments) and explains that taxi orders can be pre-filled with given details. This adds meaning beyond the schema's sparse descriptions.

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 explicitly names three services (taxi, shipment, car_rental) with specific verbs and resources, and clearly distinguishes them from sibling tools (e.g., find_flights) by focusing on ground transport. Each service has its own explanation, making the tool's purpose 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?

It provides clear context for when to use each service (e.g., taxi for ordering a taxi/transfer, shipment for sending parcels, car_rental for renting a car). However, it does not explicitly state when not to use this tool or name alternative tools, though the sibling names imply alternatives like find_flights for air travel.

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