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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful return behavior beyond that: it returns the city's airports plus nearby airports within a 250 km radius, which is genuine behavioral 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?

Front-loaded with the core purpose, then the fuzzy-match capability, then the radius/use-case note. Two clauses with no page-filler; the parenthetical examples are brief and earn their place by clarifying the 'nearest airport' behavior.

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 returns (city airports + airports within 250 km), and it does so adequately. It leaves finer details like result ordering or result count unspecified, but nothing critical to invoking the tool is missing.

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?

With 100% schema coverage the baseline is 3, but the description adds real semantics the schema lacks: the query tolerates typos and accepts both Russian and English input. That materially expands how an agent can phrase the 'query' parameter beyond the schema's bare 'Название города или аэропорта'.

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 ('найти город или аэропорт и его код IATA') plus the lookup key ('по названию'). Clearly distinguishes itself from flight-search siblings like search_flights, cheapest_prices, and get_booking_link, which operate on routes rather than place resolution.

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 concrete usage context: useful when the city has no airport (Паттайя, Анапа зимой) or when a neighboring airport is cheaper. It stops short of explicitly naming an alternative sibling for comparison, but the when-to-use conditions are clear and actionable.

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