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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds no behavioral context beyond restating the subject matter: it does not clarify data currency, geographic coverage limits, or what 'index family' means. With annotations carrying the safety load, the description contributes little.

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 no waste, front-loading the resource. It is efficient, though its brevity is purchased at the cost of useful detail rather than being information-dense.

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?

Output schema exists, so return values need not be explained, and the input schema fully documents parameters. The remaining gap is guidance on usage and scope relative to the numerous numbeo siblings, which the description does not fill. Adequate but with clear gaps.

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 both parameters are documented in the schema, so the baseline is 3. The description's phrase 'index family' loosely echoes the 'index' parameter but adds no syntax, allowed values, or formatting detail beyond what the schema already 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 the resource ('Numbeo country data for an index family') and mentions a by-city breakdown, which hints at the country-level scope. However, it lacks a clear verb and does not explicitly differentiate itself from close siblings like numbeo_indices_city or numbeo_indices_rankings_by_country. The purpose is understandable but vague.

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 guidance on when to use this tool versus alternatives. It never mentions numbeo_indices_city, numbeo_indices_rankings, or the cost-of-living siblings, nor any prerequisite or context. An agent must infer usage entirely from the name.

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