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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint: false, so the safety profile is well covered. The description adds the useful behavioral detail that type 'all' includes scheduled flights and that the result contains scheduled and actual times, but it does not disclose pagination, limits, or exact return shape. This is adequate given the annotations but not rich.

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 tight: one purpose sentence, one id-format sentence, one type-selection sentence, and one compact example. It is front-loaded with the core action and contains no filler or redundant elaboration.

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 no output schema, the description adequately conveys that the result is a list of flights with scheduled and actual times. The remaining parameters start and end are covered fully in the schema, and annotations cover side-effect concerns. A small gap is the lack of any mention of date-range constraints or return-size behavior, but nothing critical is missing for selecting and invoking the tool.

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 all five parameters already documented meaningfully. The description's id and type guidance mostly restates the schema, and while the inline invocation example is helpful for showing how to pass _apiKey, it adds little new semantic meaning beyond what the schema already provides.

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: 'List flights at an airport' and immediately clarifies arrivals/departures with scheduled and actual times. It also explains the id format and type options, making the tool's purpose unmistakable and clearly distinct from the single-flight sibling tools like flightaware_flight_status and flightaware_flight_track.

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?

The description gives clear operational guidance: how to specify the airport code, how to choose arrivals/departures/all, the default behavior, and a working example. It does not explicitly name the single-flight siblings as alternatives, but the airport-level framing makes the selection context clear enough.

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