undata_compare_countries

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

No annotations are provided, so the description carries the behavioral burden. The description discloses the return structure (organized by series → country → year) which is useful behavioral context. However, it doesn't describe data limits, response size, pagination, error handling, or whether missing data for a country is handled gracefully. It's a read-only query but that's implied rather than stated.

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, each delivering meaningful information: what it does, how to call it, and what the return looks like. No filler or repetition. It could arguably drop the last clause but the return structure note is genuinely useful for an agent predicting output shape. Well front-loaded.

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 4 parameters, no output schema, and no annotations, the description does a reasonable job but has gaps. It explains the countries parameter (ISO-3 codes), series (WDI codes), and year range, and gives the output structure. However, for a comparative analysis tool across countries, it doesn't address cardinality/limits (max countries per call), nor whether missing series for certain countries returns nulls or errors. Decent but could be richer.

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 0%, so the description must compensate for undocumented parameters. The description adds some meaning: it mentions ISO-3 codes for 'countries', WDI series codes for 'series', and a year range for start/end_year. However, it doesn't clarify the year format (string vs number), whether end_year is inclusive, or the null-handling behavior of the optional parameters beyond the defaults.

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 states a clear purpose: compare World Development Indicators across multiple countries. It specifies the verb 'compare', the resource ('World Development Indicators'), and the multi-country scoping, which distinguishes it from the sibling tools dealing with single-country data (get_country_profile) or listing/searching (list_dataflows, search_wdi_series). It doesn't explicitly differentiate from get_wdi_data but the comparative framing is distinct enough.

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?

The description provides concrete usage guidance: use ISO-3 country codes, optionally restrict to WDI series codes and a year range. It explains the comparison is organized by series → country → year. It gives clear context for when to use it (comparative analysis across countries) but doesn't explicitly state 'when not to use' or name alternative tools, so not a 5.

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