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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds value beyond that by disclosing the data source (MyNomadWorld dataset) and the shape of each result (income requirement, length, family option), which matters because no output schema exists. It does not mention default page size, ordering, or behavior when the income filter yields nothing.

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 sentence that front-loads the resource and dataset scope, then appends the optional filter. No filler or redundant restatement of the title.

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 3-optional-parameter read tool with strong annotations and no output schema, the description covers source, returned fields and the income filter adequately. The only meaningful gap is paging behavior around `limit`, which an agent calling a list tool would want to know.

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 67%: region and monthly_income_eur are already documented, and the description's income phrasing merely restates the schema's "at or below this" semantics. The undocumented `limit` parameter gets no explanation of its default or whether results are truncated, so the description does not compensate for the remaining coverage gap.

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?

Uses a specific verb ("Lists") with a precise resource ("countries that offer a digital nomad or remote-work visa in the MyNomadWorld dataset") and names the fields returned (income requirement, length, family option). It is distinguishable from country_profile and compare_countries by its list-shaped, visa-focused scope, but it never explicitly contrasts itself with the closest sibling, recommend_countries.

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?

"Optionally only those the user qualifies for on income" gives one conditional usage hint tied to the income filter. There is no statement of when to prefer this over recommend_countries or country_profile, and no exclusions or prerequisites, so the agent must infer the routing.

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