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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real value beyond that: it discloses that responses include an official source and check date, and flags that content is general information rather than legal advice — a useful caveat for downstream use.

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 the substantive answer scope and closed with the disclaimer. No filler; the phrasing is slightly telegraphic but every clause contributes.

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 read-only single-param lookup with no output schema, the description effectively describes the returned content (requirements, registrant, document, consequences, source, date). What remains unstated — output shape/format and error behavior for unknown countries — is minor.

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?

Single parameter with 100% schema description coverage ('Country id, ISO code or English name'), so the schema carries the semantics. The description adds nothing about accepted country formats or fallback behavior, which is the baseline 3 case.

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 enumerates precisely what the tool answers: whether registration is required, who must register, which document, and consequences. That is a specific resource with defined output scope, and it is clearly distinct from the sibling package/country tools. It lacks an explicit verb ('returns'/'looks up'), which keeps it short of 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 topical framing (SIM registration per country), but there is no statement of when to prefer this over siblings or any exclusion. The 'not legal advice' line hints at scope but not at routing.

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