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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so safety behavior is covered. The description adds one genuinely useful behavioral detail beyond them: 'where available' warns that gate/terminal fields may be absent. It says nothing about freshness, caching, or error behavior when a flight number is unknown.

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 lean sentences, front-loaded with the payload of returned fields and followed by the arg format. No filler, no repetition of the tool name.

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 values need not be explained, and the one required parameter is fully covered with an example; annotations cover the safety profile. The only shortfall is the absence of any routing context against the large set of sibling aviation tools.

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 0%, so the description carries the burden, and it does: the single arg is documented as an IATA flight number with a concrete example ('UA1'). Minor ambiguity remains (case sensitivity, whether a date is ever needed for ambiguous flight numbers).

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 names a specific resource and enumerates exactly what it returns (departure/arrival airports, scheduled/estimated/actual times, delays, gate, terminal), which clearly separates it from siblings like flight_wifi or aircraft. It stops short of explicitly contrasting itself with those siblings, so it is clear but not self-differentiating.

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, no prerequisites, and no mention of alternatives among the many aviation siblings (flight_wifi, aircraft, airport_conditions). Only the word 'Live' hints that this is for current rather than historical status.

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