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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior, so the bar for extra disclosure is lower. The description adds valuable behavioral context beyond those hints: it is keyless, uses official World Bank data, accepts friendly indicator names or raw World Bank codes, and accepts ISO2/ISO3 codes or common country names.

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 compact, front-loaded with the core purpose, and every sentence contributes useful information. The friendly indicator list and country-format examples are dense but not verbose, and there is no filler or redundant restatement of annotations.

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 simple read-only data retrieval tool with no required parameters and a fully described schema, the description covers the essential call context: data source, keyless access, indicator flexibility, and country input formats. It does not describe the return shape or time-series frequency, but no output schema exists and the purpose is simple enough that this is a minor gap.

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%, so the description need not restate parameter semantics; baseline is 3. It does add a little extra value by giving concrete country examples ('US', 'China', 'Germany') and reaffirming the raw World Bank code option for indicators, but it adds nothing new about start_year or end_year behavior.

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 clearly identifies the tool as returning a time series for a World Bank development indicator for one country, and distinguishes it from worldbank_compare and worldbank_country_profile via the 'one country' scope. It lacks an explicit verb like 'fetches' or 'returns', but the resource and scope are specific and unambiguous.

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 phrase 'for one country' implies this is for single-country indicator series, and listing friendly indicator names provides useful context. However, it does not explicitly name alternatives such as worldbank_compare for cross-country comparisons or worldbank_country_profile for broader country data, nor does it state when not to use this tool.

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