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

Annotations already declare readOnlyHint, idempotentHint, and closed-world behavior, so the safety profile is covered. The description adds genuinely new context about what the payload contains — scoring scale, per-metric leaderboard page, and bar-type slugs — which matters because there is no output schema. It does not describe ordering, size, or format of the returned collection.

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 sentences, front-loaded with what the tool returns and closed with the actionable usage hint. Every clause carries distinct information, and nothing is repeated from the title or annotations.

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 zero-parameter lookup with no output schema, the description covers the essential question of what comes back and why the agent would call it. A more explicit note on how the metric slugs link to top_lounges values (e.g., that bar types and metrics are both valid 'by' inputs) would make it fully self-sufficient.

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?

There are zero parameters, so the baseline of 4 applies and no parameter explanation is owed. The description's reference to the "by" argument belongs to top_lounges rather than to this tool's schema, which is appropriate framing but not parameter documentation.

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 the concrete resource (metric slugs a lounge is scored on, the 1-5 scale with what a 5 means, each metric's leaderboard page, and bar-type slugs), which is far more specific than the name alone. It also implicitly separates this from the sibling metric tools (get_airline_metrics, get_amenity_metrics, get_ship_metrics) by tying itself to lounges and to top_lounges.

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?

It gives an explicit routing instruction: "Use for the 'by' argument of top_lounges," which tells the agent exactly when this reference data is needed. It stops short of a 5 because there is no statement of when not to call it or of a competing alternative for the same vocabulary.

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