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

Annotations already establish this as a safe, idempotent, read-only, closed-world lookup, so the description doesn't need to restate that. It adds genuinely useful behavior beyond the annotations: the answer covers two separate legal regimes (FADP and GDPR adequacy lists) and the lists are volatile, so results should be re-checked before being relied upon.

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?

Three sentences, front-loaded with an explicit usage trigger, followed by what is evaluated and a freshness caveat. No filler; the example list adds disambiguation value rather than noise.

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 no output schema, the description does convey the shape of the answer (a per-regime determination on whether safeguards are needed). It does not say how the two jurisdictions are reported separately or what happens for non-adequate countries, leaving a small gap for a lookup tool with only two inputs.

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 both parameters (country code and lang) are already documented in the schema. The description restates the ISO 3166-1 alpha-2 format, duplicating schema content, and says nothing about the lang parameter — the 3 baseline 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?

States a specific check — whether transferring personal data to a given country is permitted without further safeguards under both the Swiss FADP and EU GDPR adequacy lists. The verb+resource combination and the dual-jurisdiction framing distinguish it from siblings like which_laws_apply or fadp_obligations.

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?

'Use when someone asks whether they may use a provider or send personal data to another country' gives a clear triggering condition, reinforced by concrete examples (cloud, hosting, CRM, US services). It stops short of naming an alternative sibling or stating exclusion conditions, so it is clear context rather than full routing guidance.

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