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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context: a monetary cost of $0.01 USDC via x402, which changes how an agent should budget and batch calls. It also enumerates the returned data fields, useful given there is no output schema.

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?

The capability statement is front-loaded in the first sentence, followed by short purpose and cost sentences. The return-field enumeration is somewhat list-like but every element is substantive; no filler or repetition.

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 only two parameters, no output schema, and full annotation coverage, the description supplies what an agent needs: the standardized outputs to expect, the use cases, and the payment cost. Minor omissions remain — what happens for an unrecognized country and how the x402 payment is actually settled — but the definition is largely self-sufficient.

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 both parameters are already documented. The description reinforces the 'any language or format' semantics of the country input but says nothing about the 'algorithm' parameter, leaving its purpose to the schema. Baseline 3 is appropriate when the schema carries the load.

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 uses a precise verb and resource — standardizes a country name and returns ISO 2/3-letter and numeric codes, currency, domain, calling code — which is far more informative than the tool name alone. The only gap is that a near-identical sibling, interzoid_country_standard, exists and the description does nothing to distinguish this tool from it.

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 lists broad application areas (address normalization, localization, payments, data enrichment), which implies when the tool is relevant. However, these are generic use-case labels rather than selection guidance, and with an obvious overlapping sibling (interzoid_country_standard) the description gives no rule for choosing between them.

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