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

Annotations already declare readOnlyHint=true, openWorldHint=false, destructiveHint=false, so the safety profile is covered. The description adds the aggregation semantics and which dimensions are returned, but says nothing about data scope (lifetime vs date-bounded), rate limits, or handling of unknown ICAO codes.

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?

Two sentences: the first front-loads what is returned, the second gives the input format. No filler, no restatement of the tool name, and parameter guidance follows rather than precedes the purpose.

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?

An output schema exists, so return-value details need not be spelled out, and the description still enumerates the key metrics plus the input format — enough for correct invocation. The only residual gap is that it doesn't say whether the stats span all time or a bounded period.

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 0% for the single 'code' parameter, so the description carries the full burden and does it well: it names the identifier as an ICAO code, specifies 4 uppercase letters, and gives a concrete example (WADD for Bali) that resolves ambiguity with IATA codes.

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/scope ('aggregated stats for one airport') and enumerates the returned dimensions: departures, top destinations, top aircraft, departures by year. This implicitly separates it from arrival- or trend-oriented siblings, but no sibling is named explicitly, so it falls just short of the top band.

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?

Usage is only implied: the agent can infer 'get stats for one airport' from the phrasing, and the ICAO note steers parameter format, but there is no explicit when-to-use versus alternatives (e.g. Flight_airport_arrivals_by_country, Flight_airport_arrival_trend) and no stated preconditions or exclusions.

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