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

The description discloses the exact computation method: great-circle distance with standard routing allowance, divided by published cruise, plus ground time, and a fuel-stop determination. It also explains that the result is an indicative broker estimate and that AviationHS is not a direct air carrier. This goes well beyond the readOnlyHint annotation and provides meaningful operational context.

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 compact and front-loaded with the core calculation and output. Each sentence earns its place: the formula, the indicative nature, and the regulatory disclaimer. The legal sentence is relevant because it frames how the result should be presented.

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?

There is no output schema, so the description carries the burden of explaining what the tool returns. It mentions the fuel-stop flag and the inputs to the calculation, but it does not specify the output format or units, nor does it clarify accepted input formats for from/to/aircraft. This is adequate for a simple estimator but leaves some ambiguity for an agent.

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%, so the baseline of 3 applies. The tool description does not add material parameter-level guidance beyond what the schema already says: it does not explain what values from/to expect or how aircraft should be specified. The formula context is useful but does not clarify parameter formats.

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 clearly conveys that the tool calculates an indicative flight time using great-circle distance, routing allowance, cruise speed, and ground time, and that it also indicates whether a fuel stop is needed. It does not use an explicit 'estimates flight time' verb phrase, and it does not distinguish itself by name from siblings, though the legal disclaimer separates it from quote/offer tools.

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 implies this is an indicative planning estimate rather than a binding quote or offer, which hints at when to use it. However, it does not explicitly state when to use this tool instead of siblings like get_quote or check_runway, nor does it provide exclusions.

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