Search airports

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

Annotations cover the safety profile (readOnly, idempotent, closed-world), and the description adds non-obvious operational facts on top: it runs offline from a bundled OurAirports dataset, consumes no API credits, and ranks larger airports first. These materially affect how an agent budgets calls and interprets result ordering.

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?

Three sentences, front-loaded with the core capability and immediately followed by the routing guidance and the cost/ranking caveats. No sentence is filler; each adds distinct information.

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 read-only lookup with a fully documented two-parameter schema, the description covers purpose, workflow position, cost model, and ordering. The only mild gap is the exact shape of a returned record (fields available per airport), which no output schema supplies, but the intended use case does not strictly require it.

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%, so the baseline is 3; the description goes slightly beyond by giving worked examples of query inputs and by explaining that results are size-ranked, which informs how the limit parameter should be set. It adds context rather than merely restating the schema.

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 verb (Find) plus resource (airports) and enumerates the searchable keys (city, airport name, country, IATA/ICAO code) with concrete examples. An agent can immediately distinguish it from siblings like search_flight_prices or get_airport_schedule, which consume codes rather than resolve them.

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?

Explicitly says 'Use this first' and names the downstream tools (search_flight_prices, get_flight_status, get_airport_schedule) that require the IATA codes this tool produces. The when-to-use condition and the alternative-avoidance path are both spelled out, leaving nothing to inference.

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