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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds useful data-scope context (9,500 airports, includes coordinates, elevation, country, region, city), but it also implies behaviors the single 'code' parameter cannot support. No output schema exists, yet the description gives only a partial picture of what is returned.

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 opening is a near-verbatim triple restatement ('Airport by IATA/ICAO code. Airport by code. Airport lookup by IATA or ICAO code...'), which is pure padding. The front-loaded clause is fine, but the redundancy and feature-list sprawl waste the reader's attention.

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 single-parameter lookup tool this should be simple, but the description advertises search-by-name, nearest-airport and distance/flight-time features that the schema cannot deliver with only a 'code' argument. With no output schema, the description should clarify return shape; instead it leaves the agent with an inflated and partly unachievable capability picture.

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% and the sole 'code' parameter is fully documented with IATA/ICAO examples, so the schema carries the burden; baseline 3 applies. The description adds no syntax or format detail beyond the schema, and its claims about name/city search and coordinates are not backed by any parameter.

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 core purpose is stated ('Airport by IATA/ICAO code'), which is a specific verb+resource. However, the description then bolts on capabilities that belong to siblings ('search by name or city', 'nearest airports to any coordinates', 'distance and flight time between two airports'), muddying what this tool actually does versus airport_search and airport_distance. The result is a vague, over-broad purpose rather than a crisp one.

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?

There is no when-to-use guidance and no mention of the obvious alternatives among siblings (airport_search, airport_distance, distance_between_places). By claiming to also do search-by-name and airport-to-airport distance, it actively competes with those siblings without telling the agent which to pick.

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