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

Annotations already declare readOnly/idempotent/non-destructive and closed-world, so the safety profile is covered. The description adds material behavioral context beyond that: the access-tier requirement and the caveat that gate relevance is categorical rather than walking distance, which prevents misinterpretation of results. It stops short of describing matching or empty-result behavior, so not 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?

Two sentences, zero filler, and the access prerequisite and search scope are front-loaded before the return-value detail. Every clause carries information.

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 read-only search with full annotation coverage and an output schema, the description covers access requirements, search scope, returned field categories, and the key gate-relevance caveat. Minor omissions (matching semantics, behavior on zero results) keep it just short of complete.

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 is 3. The description mirrors the schema parameters (IATA, terminal/gate) without adding syntax or interaction rules, and says nothing about max_results; the one nuance it adds concerns result interpretation rather than parameter usage.

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 ('Search Tineo's populated first-party airport-lounge catalog') and narrows scope by key ('by IATA and optional terminal/gate'). This is clearly distinguishable from sibling search tools like search_hotels, search_attractions, and places_search without opening a schema.

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 a real eligibility prerequisite ('Requires Tineo Ultra access'), which is useful context, but says nothing about when to prefer this over alternatives or when it is inapplicable. Usage is implied rather than stated, so a 3 is appropriate.

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