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 read-only safety profile is covered. The description adds valuable behavioral context beyond annotations: it discloses that data is curated country-level estimates replacing a discontinued API and warns the agent to verify locally.

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?

The description is compact and front-loaded, using two sentences to convey scope, metric composition, output categories, data provenance, and a trust caveat. Every clause adds information; there is no padding or repetition.

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 tool with an output schema and fully documented parameters, the description is complete enough: it explains the ranking methodology, the key metrics, return categories, and the reliability caveat. An agent has sufficient context to invoke it correctly without additional clarification.

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 the schema already documents all five parameters. The description adds useful context by noting that budget drives lifestyle labels and visa eligibility and that weights are user-selected, but it does not need to restate parameter syntax or types.

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 clearly states a specific verb and resource: it ranks 41 countries by a weighted composite of livability metrics versus cost. It distinguishes itself from sibling comparison tools by emphasizing ranked, multi-country scoring rather than pairwise or single-aspect comparisons.

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?

The intended use is strongly implied: use this when you want a weighted quality-of-life vs cost ranking across many countries. However, it never explicitly names sibling alternatives like compare_countries or select_region, nor does it state when not to use this tool.

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