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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds valuable context beyond annotations: the returned total is indicative, the booking form confirms the exact figure, and outside-London trips have extra rules. No contradiction with 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?

Two information-dense sentences with no filler. The main product and rules are front-loaded, and the indicative-total caveat closes the description efficiently. It could be slightly tighter, but it earns each phrase.

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 price-quoting tool with six parameters and no output schema, the description covers the core scope, pricing rules, and return behavior. It does not describe every parameter, but the schema fills most gaps and the missing pieces (language, passenger count) are unlikely to cause incorrect invocation.

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 67%, so the description partially compensates. It adds meaningful pricing semantics: 4-hour minimum in London, 8-hour minimum outside London, distance fee beyond 20 miles, and Manchester day rate. Some parameters like passengers and language are left to the schema, but those are self-explanatory.

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 names a specific resource (chauffeur-driven Mercedes in London), the pricing modes (hourly, 8-hour full-day), and the geographic scope (London and outside London). This clearly distinguishes it from sibling tools like get_transfer_price or get_meet_greet_price.

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?

The context is clear: use this for hourly or full-day chauffeur pricing, not for transfers or meet-and-greet services. It does not explicitly name alternative tools or state when not to use it, but the scope and rules strongly imply the intended use.

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