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

Annotations already cover readOnlyHint, destructiveHint, idempotentHint, openWorldHint. The description adds that it returns indicator codes for use with who.data, which is not behavioral but contextual. No contradictions.

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 core purpose and examples; no redundant wording. Efficiently conveys what the tool does and its output.

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?

Given the tool's simplicity, the description covers the purpose and output usage well. Output schema exists (though not shown), so return values are documented. Slightly lacking in pagination details but not essential.

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?

Input schema provides full descriptions for both parameters (search and limit). The description does not add additional meaning beyond the schema, so baseline 3 is appropriate for 100% schema coverage.

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?

Clearly states it lists 1,000+ WHO Global Health Observatory indicators, with specific examples (life expectancy, mortality rates, etc.). Differentiates from siblings like who.health.countries and who.health.data by mentioning returns indicator codes for use with who.data.

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?

Describes purpose and explicitly notes that returned codes are for use with who.data, providing context for follow-up actions. Does not explicitly state when not to use, but the sibling context and the tool's role as a list are clear enough.

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