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

With only readOnlyHint=true provided, the description carries rich behavioral context: prices are locked at booking with no surge, the no-fixed-price response is disclosed, and the return payload (book_url per vehicle in book_urls) is described despite the absence of an output schema.

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 dense sentences, front-loaded with the core purpose and ending with the actionable instruction. Some clauses (GST and tolls, no surge) are compact value-adds rather than filler, though it runs slightly long.

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 13-parameter pricing tool with a nested seats object and no output schema, the description covers pricing semantics, the no-price edge case, and the return structure (book_url/book_urls). Nothing an agent needs to call it or relay results is missing.

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 100%, so the baseline is 3; the description adds rationale by explaining that date, time, passengers, return leg, luggage, child seats and flight should all be passed because they are embedded into the generated book_url, which the schema only partially conveys.

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 resource and scope: exact fixed transfer prices from the live booking engine, per vehicle, AUD, GST/tolls included. An agent can distinguish this pricing lookup from check_availability, get_service_info, and request_booking without inspecting any 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 operational guidance: pass all trip details so the link carries them, hand the customer book_url rather than describing the form, and never estimate a figure if no fixed price exists. It does not explicitly name the sibling tools (e.g. request_booking) or state when to prefer them, so it falls short of a 5.

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