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

Annotations only declare readOnlyHint and openWorldHint; the description adds real behavioral context on top of that, namely the CC0 licensing of the airport file, per-source licensing for covered fields, that no points are spent, and the privacy_consent_required error path. The consent sentence is somewhat confusing because 'if you supply fields' does not map cleanly onto a schema with a single required `code`, which keeps this from being a 5.

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 definition leads with what the tool returns and follows with constraints in short, declarative sentences. The privacy-consent sentence is the weakest part, both for its length and for its unclear reference to 'fields'.

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 one-parameter, read-only tool with no output schema, the description covers the return contents, licensing, cost, and the main failure mode. The only meaningful gap is the meaning and format of the `code` argument.

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%, so the description is responsible for explaining the one parameter, and it says nothing about `code` at all. The schema's pattern '^[A-Z]{3}$' hints at a three-letter code, but the description never confirms whether this is IATA or ICAO or gives an example.

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 uses a specific verb and resource ('Read one airport file from AirportMiles') and enumerates what comes back: identity, coordinates, and up to eight published routes. It never names a sibling, so an agent must infer that hub_geocode or hub_wikidata are the alternatives, which keeps it below a 5.

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 negative scoping is clear: no live flights, no URL input, no point spend. But there is no positive 'use this when...' guidance and no routing to or away from sibling hubs, so the agent has to infer the selection criteria itself.

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