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

No annotations are provided, so the description bears the full burden. It does disclose a genuine non-schema trait — the cost of 1 credit — plus the default indicator behaviour, which is useful. However, it says nothing about the returned data shape, available year granularity, or whether calls are metered per request, leaving real gaps for a no-annotation tool.

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 compact clauses with the core capability front-loaded and the cost annotation trailing. Nothing is wasted, though the parenthetical cost phrasing is slightly telegraphic.

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 three-parameter lookup with no output schema and no annotations, the description covers the essential identity, the default indicator, and the credit cost. It falls short on what the response looks like (series vs single value, year granularity) and on how to supply multiple years, which an agent must guess.

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 baseline is 3. The schema labels are themselves thin ('number' for years, 'ISO2/3' for country), and the description compensates only for the indicator parameter by naming the default GDP/current US$ — it adds nothing about the years or country formats beyond the schema.

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: World Bank indicator values by country, with the default indicator named (GDP, current US$). It is unambiguously distinguishable from the sibling tools, which cover unrelated domains (EU tenders, SEC filings), though it doesn't explicitly contrast with them.

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?

Usage is implied by the domain — an agent can infer this is the tool for country-level World Bank statistics — but there is no explicit when-to-use framing, no guidance on choosing an indicator vs defaulting to GDP, and no exclusions. Given the siblings are different domains, minimal explicit routing is arguably acceptable, so a 3 rather than lower.

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