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

Annotations already declare readOnlyHint and idempotentHint, so the description correctly avoids repeating those. It adds meaningful behavior: substring match semantics, pagination via offset with hasMore/nextOffset, and the fact that an out-of-range offset returns an empty array rather than an error. This is rich disclosure beyond the structured 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, front-loaded with the primary purpose, followed by usage examples and a pagination caveat. No redundant language, and every sentence adds useful context.

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 simple search tool with a full output schema (hasMore/nextOffset referenced), the description covers purpose, usage, matching behavior, pagination, and failure modes. An agent has everything needed to call it correctly without ambiguity.

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 100%, so parameters are already documented. The description adds value by providing concrete example search terms (e.g., life expectancy, immunization) and clarifying offset behavior beyond the schema note (e.g., reading hasMore/nextOffset, empty result behavior). This goes beyond the baseline but does not fully rewrite parameter docs.

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 states a specific verb (search), resource (WHO GHO indicator catalog), and criterion (keyword in indicator name). It differentiates from siblings like who_list_indicators by emphasizing the substring search and by explicitly linking the returned codes to who_query_indicator_data, making the tool's role clear.

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?

Provides clear context: the tool is for finding indicator codes/names to pass to who_query_indicator_data. It offers example keywords and explains pagination refinement for truncated results. However, it does not explicitly contrast with sibling tools like who_list_indicators or when to prefer one over the other, so it stops short of a full when/when-not comparison.

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