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

Annotations already mark the tool readOnly, idempotent, and non-destructive, and the description adds meaningful behavioral context: it returns booking pages for private and shared transfers, and it requires affiliate commission to be disclosed when links are presented. This is valuable beyond the annotations and does not contradict them.

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 dense but every sentence earns its place: core output, use-case triggers, exclusions, and the affiliate disclosure. The main action is front-loaded and the rest is structured efficiently.

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?

With 100% schema coverage, an output schema, and rich annotations, the description fills the remaining gaps: provider names, guide count, exclusions, and the disclosure obligation. An agent has enough information to decide when to call it and what to do with the returned links.

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%, with clear per-parameter descriptions for city, lang, airport, and country. The tool description adds general context about what the parameters select, such as guides and regional programmes, but does not add syntax-level detail beyond the schema. Baseline 3 is appropriate.

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 opens with a specific verb and resource: 'Return pre-booked airport transfer links,' then enumerates exact providers and the accompanying guides. It also distinguishes itself from siblings by domain and explicitly lists what it does not do (no live quotes, no public transport timetables, no ride-hailing dispatch).

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 gives explicit triggers: 'Useful when a user asks how to get from an airport, about taxi or transfer prices, or plans a late-night arrival.' It also states clear exclusions that help rule it out, though it does not name alternative sibling tools explicitly.

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