find_nearest_airports

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

Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so the safety profile is covered. The description adds real behavioral context beyond that: `near` is resolved against both city and airport datasets, and the result carries a city code rather than an airport code. It stops short of describing distance ordering or pagination limits, which keeps it from a 5.

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 short paragraphs, each doing distinct work: what it does, when to use it versus the sibling plus the downstream handoff, and the input-mode selection. The scoping and routing guidance is front-loaded and no sentence is filler.

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 an output schema present and annotations covering the safety profile, the description only needs to carry purpose, usage routing, and input-mode selection — all of which it does. An agent has everything required to choose and call this tool correctly.

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% and the schema already documents each parameter, including the override relationship ('latitude ... Overrides `near`'). The description restates the either/or selection of `near` versus a lat/long pair but adds no format, unit, or constraint detail beyond the schema, so the baseline 3 applies.

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 and resource (find airports closest to a place or coordinates) and immediately contrasts with the sibling lookup_airports, which only matches names. An agent can distinguish the two without opening either 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 an explicit trigger ('when the user asks which airport to fly into for a town, a resort, or a point on the map'), names the alternative tool and why it fails for this question, and routes the downstream step (feed the returned city code, not airport code, to search_flights). Nothing is left to inference.

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