cheapest_destinations

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

Annotations already declare readOnlyHint and openWorldHint, and the description adds meaningful extra context: prices come from an ~48h Aviasales cache rather than a live search, and the actual price is confirmed via the returned url. This freshness caveat is exactly the kind of behavioral trait annotations can't convey.

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 sentences, zero waste: purpose and sort order first, then the canonical use case, then the data-freshness caveat. Front-loaded and tightly organized.

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 no output schema, the description does mention the returned url link and the sorted, one-per-destination result shape, which is helpful. It covers purpose, usage, and a key data caveat; only the remaining return fields and pagination behavior are left implicit.

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 every parameter (origin, limit, direct, currency, max_price, departure_at, return_at) is already documented in the schema. The description only echoes a max_price/currency example ('до 20 000 ₽') without adding format or constraint detail beyond what the schema provides.

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+resource and scope: 'Куда дешевле всего улететь из города', one cheapest ticket per destination, sorted cheap-to-expensive. This is clearly distinct from search_flights (specific flight lookup) and price_calendar (a calendar of prices), so an agent can differentiate without opening schemas.

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 an explicit use case ('куда слетать в ноябре до 20 000 ₽'), which tells the agent when to reach for this tool. However, it never names the alternatives (search_flights, price_calendar) or states when NOT to use it, so routing is only partly guided.

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