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

The annotations already declare readOnly, idempotent, openWorld, and non-destructive behavior. The description adds useful context beyond these by specifying the geographic scope (53 European countries), historical depth (back to the 1970s), and return fields (measure code, indicator name, last updated). This is sufficient behavioral disclosure for a search tool.

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 focused, front-loaded with the core purpose, and gives concrete examples of relevant indicators. The final sentence is mildly redundant with the opening, but overall the description is compact and readable without unnecessary jargon.

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?

Although there is no output schema, the description explains what is returned: the measure code, indicator name, and last-updated date. Combined with full schema coverage and safe annotations, this is nearly complete for a search-style tool. It does not describe pagination or result ordering, but these are minor for the stated purpose.

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?

The input schema has 100% description coverage for all three parameters, including query, limit, and dataset. The description does not add substantial parameter-level guidance beyond the schema, but it does reinforce the query style with named examples like 'tuberculosis incidence' and 'life expectancy.' Baseline 3 is appropriate.

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 and resource: 'Find health indicators in the WHO Regional Office for Europe Data Warehouse by name.' It also clarifies the tool's search-oriented role and that it returns the measure code needed for fetching data, distinguishing it from sibling tools like who_euro_measure_data or who_euro_list_datasets.

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 clear context for when to use this tool: to search for European health indicators by name and obtain WHO Europe indicator codes. It does not explicitly state when not to use it or name alternative tools, but the 'by name' search focus and mention that it returns the code needed for fetching data imply the intended workflow.

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