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

Annotations cover only readOnly/openWorld, and the description goes well beyond them: it discloses value lag of 1-2 years, omission of years with no published value, and full pricing/auth behavior ($0.002 USDC per successful call via x402 on Base/Solana/Arc, no charge on failure). This is exactly the kind of behavioral context structured fields don't carry.

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 tight sentences that lead with purpose, then inputs, then caveats/pricing. Dense but front-loaded and mostly waste-free; minor overlap between the indicator list in the prose and the schema enumeration.

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 an output schema present, return values needn't be explained, and the description covers source, licensing, input formats, data caveats, and payment. The one gap is lack of any routing signal distinguishing it from the 'macro' sibling.

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 coverage is 100% so the baseline is 3, but the description adds meaningful semantics beyond the schema: 'exact name' matching for country, 'raw World Bank code' acceptance for indicator, and the note that unpublished years are dropped, which shapes how 'years' should be interpreted.

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 a specific verb+resource (macro indicators from the World Bank) and enumerates the exact indicator set, so an agent knows precisely what it retrieves. It does not, however, differentiate itself from the sibling 'macro' tool, which is the most plausible alternative for a macro query.

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?

It gives input conventions (ISO2/ISO3/exact name; friendly name or raw World Bank code), which implies how to call it, but there is no explicit when-to-use guidance or exclusion relative to 'macro' or other data siblings. Usage is inferable rather than stated.

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