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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds useful context about what the services include and their geographic scope, but it does not disclose return format, currency, or how the optional chauffeur transfer affects the fixed price. The incremental behavioral detail beyond annotations is moderate.

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 a single front-loaded sentence that immediately communicates the fixed-price purpose and then packs in the service details. It is economical with no filler, though the long parenthetical makes it slightly denser than necessary.

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?

The package scope and location boundaries are well defined, which is adequate for a simple read-only price lookup. However, since there is no output schema, the description still leaves return format, currency, and guest-count impact unstated, and the optional chauffeur clause implies a service variation not fully explained by the parameters.

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?

The schema documents `guests` and `service`, and the description clarifies that `service` selects between the VIP meet-and-greet and student-pickup offerings, including the Heathrow vs. any London airport distinction. However, it adds no meaning for `language`, which is the one parameter without a schema description, and no detail on how `guests` influences the price.

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 very specific purpose: 'Fixed prices' for the Heathrow VIP Meet & Assist service and for student/unaccompanied-minor airport pickup. It names the exact service components and locations, making the resource unmistakable and clearly distinct from sibling pricing tools like get_hourly_price or get_transfer_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 description provides a clear usage context: use this tool when a fixed price is needed for the Heathrow VIP Meet & Assist package or for student/unaccompanied-minor pickup at London airports. It does not explicitly name alternative tools or exclusion cases, but the intended scope is evident.

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