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

Annotations already declare readOnlyHint=true and openWorldHint=false. The description adds useful behavioral context: cheapest-first ordering and that it returns summary rows. It doesn't mention limits, empty-result behavior, or how 'cheapest' is computed, but with annotations covering safety it is adequate.

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 compact sentences, front-loaded with what it searches, then filtering/ordering, then return-shape routing. Nothing is wasted.

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 search with no output schema, the description covers purpose, ordering, filtering semantics, and redirects to the sibling for detail. Minor gaps remain around result limits and how filters combine, but overall complete enough to call correctly.

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 50%; region and max_minimum_usd are documented in schema. The description explains max_minimum_usd semantics per visa_type (monthly income for digital_nomad/retirement, investment for investor), which is valuable beyond the schema. But it doesn't address region/countries/visa_type semantics at any added depth.

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 (Search) and resource (digital nomad, retirement, investor visas), specifies ordering (cheapest entry first), and names the sibling (get_country_profile) for deeper detail. An agent can distinguish it from list_countries and get_country_profile without opening schemas.

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?

Explicitly says to use get_country_profile for full requirements, clarifying scope. However it doesn't state when NOT to use it versus compare_countries or list_countries, so the alternative routing is only partially covered.

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