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

Annotations already cover the safety profile (read-only, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds real value beyond them: it discloses the 'few live matches' nature of the result, the one-place-per-call constraint, and the 'do not invent a handle' guard against hallucination.

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?

The core action is front-loaded in the first sentence, followed by the when-to-use condition and the chaining instructions. Every sentence carries distinct information with no filler, and the multi-line formatting makes the call sequence scannable.

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?

Even though an output schema exists and return values need not be described, the description summarizes the returned fields (handle, name, country, airport_code, place_url) specifically to enable tool chaining, which is exactly what an agent needs here. Nothing required to invoke it correctly 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?

Schema coverage is 100% and both parameters (query, page_size) are documented there with ranges and defaults, so the schema carries the load. The description adds only the 'one place per call' framing, which is closer to behavioral guidance than parameter semantics; baseline 3 is appropriate.

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?

Specific verb (resolve) plus resource scope (city, country, region, or airport onto Sorted destinations). It clearly positions itself as the entry point that produces the handles/airport codes the sibling tools consume, so an agent can place it relative to destinations.info, destinations.recommend, and destinations.weather 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?

Gives an explicit trigger condition ('when the traveler names a place and you do not already have a sitemap handle or IATA code') plus the inverse case of just going straight to a handle. It also routes the next call explicitly: handle to destinations.info/weather, airport_code to destinations.recommend. Nothing is left to inference.

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