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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description usefully adds the data scope (including that sources may be 'official or not'), but says nothing about freshness, rate limits, or what happens for a country without a wallet.

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 what the tool returns, then the required input. The content list is dense but all of it is informative about the resource; there is no filler.

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?

An output schema exists, so return shape need not be documented, and annotations cover the safety profile. For a simple two-parameter lookup the description is nearly complete; the only real gap is the undocumented `lang` parameter and the absence of explicit routing against list_countries.

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 has to compensate, and it does well for `code`: it clarifies the expected format with examples (DE, FR, AT, EL for Greece) and accepts either EU or ISO codes, resolving the EL/GR ambiguity. However the second parameter, `lang`, is never mentioned, so half the parameters remain undocumented outside the bare enum.

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 (get) and a bounded resource (details for one EU member state), then enumerates the content areas returned: wallet, status, sources, dated history, relying party register. The singular 'one country' implicitly separates it from the sibling list_countries, though that alternative is never named explicitly.

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 only implied by the phrase 'Details for one EU member state' – an agent can infer it is the per-country lookup once a code is known. There is no explicit when-to-use guidance, no mention of when to prefer list_countries or get_registers, and no stated prerequisites.

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