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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the bar is lower. The description adds operational context beyond annotations with 'No auth — WHO public data, unlimited free,' clarifying authentication and rate-limit posture. This does not contradict the annotations.

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 plus a helper cross-reference and auth note. The core action is front-loaded, and each clause carries distinct useful information with no filler.

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 a full output schema, 100% parameter schema coverage, and safety annotations already present, the description only needs to add selection logic and operational constraints. It provides use cases, country-code discovery guidance, and auth/free-tier context, leaving no critical gap.

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 covers 100% of parameters, so the baseline is 3. The description adds value by listing example indicator domains (life expectancy, immunization coverage, maternal mortality, disease burden, SDG targets) and cross-referencing who.dimension_values for valid country codes, which helps an agent populate parameters correctly.

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 opening phrase 'Get WHO health indicator data for a specific country' names a clear verb, resource, and scope, with examples of health domains. It does not explicitly name sibling tools like who.health.data or who.health.indicator_data to differentiate, so the country-specific wording must carry that distinction.

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 description gives practical context: 'Useful for country-level health profiles' and instructs to use who.dimension_values with dimension="COUNTRY" to discover valid country codes. It does not list exclusions or explicitly compare against alternative data-query siblings, so it stops short of a full when-not-to-use statement.

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