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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so the safety profile is covered. The description adds the useful detail that results include which vehicles fit, but says nothing about whether an availability result is a hold, how live the data is, or any rate/latency characteristics.

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?

A single front-loaded sentence with no filler; the scope and the result content are stated immediately. Slightly compound, but nothing is redundant enough to trim.

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 9-parameter, open-world, non-destructive check with no output schema, the description is adequate but thin: it hints at a vehicle-fitness result without describing the shape of the response or what an unavailable outcome looks like. It also doesn't mention round trips (return_date/return_time) or luggage constraints even though the schema supports them.

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%, including formats, defaults, aliases, and airport-pickup time guidance, so the schema does the heavy lifting. The description only echoes route, date/time, and passengers and adds no meaning beyond that; it ignores luggage, flight_number, and the return-trip parameters entirely.

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 ('check whether a private transfer can be booked') plus the key inputs (route, date/time, passenger count) and the return content ('which vehicles fit'). It clearly differs from get_quote and request_booking in substance, but never names those siblings explicitly.

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?

Use is implied as a pre-booking feasibility check, but there is no explicit when-to-use vs when-not guidance, and no routing to get_quote (for pricing) or request_booking (to actually book). An agent must infer the sequence from the names alone.

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