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

With no annotations, the description carries the full burden, and it discloses two important traits: the call is paid per invocation via x402 in USDC on Base, and each returned value is tagged with its year. It still says nothing about failure modes, rate limits, or quota behavior, so it falls short of full disclosure.

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?

Two sentences, front-loaded with the source and coverage before the usage hint and payment note. The first sentence is enumeration-heavy but every listed item earns its place by defining the indicator surface; no filler or restatement of the name.

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?

There is no output schema and no annotations, yet the description covers what is returned (latest years, each value labeled with its year), the granularity limits, and the payment handshake. Error handling and the exact response envelope remain unspecified, which is the only meaningful 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 every parameter (years, countries, indicators, payment_signature) is already documented in the schema and the baseline is 3. The description reinforces the 'any WDI code, up to 5 countries' constraint and mentions a 'default core set' of indicators, but adds no syntax or format detail beyond what the schema supplies.

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 names a specific source and resource (World Bank World Development Indicators) and enumerates the exact figures returned (GDP, per-capita GDP, real growth, CPI inflation, unemployment, population, debt, trade, FDI). The scope is quantified (~217 economies, up to 5 countries, up to 10 years), so an agent knows precisely what comes back without opening the schema.

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 explicitly states when to use it: 'Use when an agent needs official macro figures for a country... for research, market sizing, credit or country-risk work.' That is concrete usage context, though there are no exclusion conditions or named alternatives to route away to (none exist among siblings).

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