numbeo_indices_rankings_by_country

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

No annotations exist, so the description carries the full burden. It adds one genuinely useful behavioral fact — 'Credential-free public Numbeo data (numbeo.com)' — which informs the agent that no auth setup is needed. However, it discloses nothing about the response shape, entry count, or ordering, and there is no output schema to fill that gap for a tool whose entire purpose is returning data.

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 description is short (30 words over three sentences), but sentences one and two are near-duplicates: 'Get the global Numbeo country ranking for an index family' restates 'Returns the global country-level ranking for a Numbeo index family.' Words like 'Numbeo', 'global', and 'index family' appear twice, so it is compact but not crisp.

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 lookup tool whose parameter is fully documented in the schema, this is close to adequate. What is missing is the result format (no output schema exists) and any differentiation from several similarly named numbeo siblings, both of which an agent would need to confidently select and interpret this tool. The credential-free note is a good completeness point.

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%: the single `index` parameter is fully documented with a 6-value enum and the description 'Index family'. The tool description merely echoes 'index family' and adds no syntax, format, or default details beyond what the schema already provides, so the baseline of 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?

The description uses a specific verb and resource ('Get the global Numbeo country ranking for an index family') and conveys the granularity: country-level rankings for index families. The enum in the schema further pins down which index families are supported. It loses a point because sentences one and two say essentially the same thing, and it does not explicitly distinguish itself from the near-duplicate sibling numbeo_indices_rankings.

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?

No when-to-use or when-not-to-use guidance is provided. This matters here because several siblings are near-identical in name (numbeo_indices_rankings, numbeo_indices_country, numbeo_cost_of_living_rankings_by_country), and the description gives an agent no criteria for choosing among them. The only implied signal is 'index family' in contrast to cost-of-living tools, which is weak.

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