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

Annotations already mark this as read-only and non-destructive. The description adds meaningful behavioral context: it calls the World Bank API, returns JSON, and costs $0.005 USDC via x402. It doesn't detail response structure or error handling, but the annotation coverage lowers the bar.

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?

A single compact sentence packs the purpose, scope, source, format, and pricing with no wasted words. The key information is front-loaded, and every clause adds value.

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 lookup with two well-documented parameters and strong annotations, the description is nearly complete. It specifies the output format as JSON but doesn't describe the exact response shape or failure behavior; still, the stated purpose and source are enough for an agent to invoke it correctly.

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 descriptions already cover both parameters with ISO2/ISO3 and an indicator code example. The description's examples of indicator categories are illustrative but not essential; no meaningful semantic information is added beyond the schema, so the baseline 3 applies for 100% coverage.

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 states a specific verb ('lookup') and resource ('World Bank indicator ... for a country'), with illustrative examples of indicator types. It clearly identifies the World Bank API as the source, distinguishing it from any sibling tool, none of which offer World Bank data.

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 description implies use when needing the latest World Bank indicator value for a country, and 'Latest value' sets an expectation of current data. It doesn't explicitly name alternatives or exclusion conditions, but no sibling tool covers the same domain, so the context is sufficient.

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