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

Annotations already cover the safety profile (read-only, idempotent, open-world, non-destructive), so the description adds value by naming the upstream source (cwsi.net Lounge Finder) and disclosing the coverage limit of about 106 airports, which warns the agent about potential gaps. It does not say what happens for an unsupported code (empty vs. error), leaving a small gap.

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?

Three tight sentences: purpose and fields first, then the required input format, then coverage limits. No filler, and the most actionable constraint (IATA code) is front-loaded near the top.

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 an output schema present, the description doesn't need to explain return values, and it already summarizes them plus the data source and coverage. The only shortfall is not stating behavior for out-of-coverage or invalid airport codes, which matters given the open-world, limited-coverage data set.

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% and the single parameter is fully documented in the schema, including case-insensitivity and format. The description's IATA-code hint largely repeats the schema rather than adding new semantics, so the baseline 3 applies.

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 and resource ('Airport lounges at an airport, grouped by terminal') and enumerates the returned fields (name, brand, concourse/gate, hours, access rules). An agent can immediately distinguish it from the sibling tools, which are all mileage calculators and fare-class lookups.

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?

Gives clear invocation guidance: 'Give a 3-letter IATA code such as ATL,' plus the geographic scope (~106 airports across listed regions) that tells the agent when the tool will and won't have data. There is no explicit when-not/alternative routing, but no sibling covers lounges, so the omission is minor.

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