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

With no annotations, the description carries the full behavioral burden and does it well: it discloses the payment rails and cost (0.01 USDC via x402, 12 sats Cashu NUT-24, or 12 sats Lightning L402), the license (CC BY 4.0), and the return shape (rows plus a ready-to-save CSV). It does not mention rate limits or failure behavior, which keeps it from a 5.

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?

It is a single dense block, but the core scope (indicator, country, year range) is front-loaded before the return, license, and pricing details. Every clause carries information; the heavy parentheticals make it slightly run-on but nothing is wasted.

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 4-param tool with no output schema and no annotations, the description covers the query semantics, result format, cardinality limits, licensing, and payment requirements. Only error/edge-case behavior is absent, which is a minor gap rather than a blocking one.

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, and it does for all four parameters: indicator (alias list plus a concrete WDI code example like NY.GDP.MKTP.CD), country (up to 20 ISO codes with the AU;NZ;US syntax), and from/to (year range with the from=2015&to=2025 example). Format syntax is supplied for each, which the bare schema lacks entirely.

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 resource (World Bank open data) and precisely scopes it: one indicator, up to 20 ISO country codes, a year range. An agent can tell this apart from dataset_fx by the 'World Bank' qualifier and the WDI indicator vocabulary. It stops short of an explicit verb or a direct sibling comparison, so it lands just below a 5.

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 resource description and the detailed indicator alias list, which signals the intended query type. However, there is no explicit when-to-use / when-not-to-use statement and no named alternative (e.g. dataset_fx, fx_rates) for the agent to route between. This is implied guidance only.

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