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

Annotations already declare readOnlyHint=true and openWorldHint=true, and an output schema exists, so the safety and return-shape burden is largely covered elsewhere. The description adds no behavioral context of its own — no note on exact-match vs fuzzy lookup, error behavior for unrecognized country names, or caching/rate limits.

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?

A single short sentence with the resource and lookup key front-loaded and zero filler. Nothing could be removed without losing 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 one-parameter read tool with annotations and an output schema, the description is minimally sufficient — the agent can call it correctly. But amid hundreds of siblings, it omits what the record contains and how it differs from the neighboring numbeo and datasets_numbeo tools, leaving selection partly guesswork.

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%, and the country parameter is documented with spelling guidance ('as Numbeo spells it, e.g. Vietnam'). The description's 'by country name' merely restates the parameter, adding no new syntax or format detail, so the baseline of 3 applies.

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 a specific resource ('Numbeo countries dataset record') and a specific retrieval key ('by country name'), so an agent knows it fetches a single country-level record. It does not, however, state what the record contains (cost of living? indices?) or distinguish itself from numbeo_cost_of_living_country or numbeo_indices_country.

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?

There is no when-to-use guidance and no mention of alternatives such as datasets_numbeo_countries_search for discovery or datasets_numbeo_cities_item for city-level data. The single-record nature is implied only by the 'item' suffix and the description text.

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