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

Annotations already declare read-only, idempotent, and non-destructive behavior, so the bar for extra disclosure is lower. But the description claims 'list every health indicator' while the input schema includes a limit parameter with a default of 100, implying the result may be truncated. The description does not disclose this limit or pagination behavior, which is a misleading gap.

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?

Three concise sentences with the core action front-loaded. The second sentence about returning codes and names is slightly redundant with 'list every health indicator,' but overall it is efficient and scannable.

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 no output schema, the description partially compensates by stating return contents (codes and names), but it omits limit/pagination behavior, which is essential for a 'list every' claim. For a simple 2-parameter tool this is adequate but not complete.

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% for both parameters. The description repeats the dataset examples already present in the schema and adds no new meaning about the limit parameter or value formats. Per baseline rules, this scores 3.

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 opens with a specific verb and resource: 'List every health indicator inside one WHO Europe dataset.' It names concrete dataset examples (HFA, HFAMDB) and states the output ('indicator codes and names'). This clearly scopes the tool to a single dataset, distinguishing it from sibling tools like who_euro_list_datasets or who_euro_search_measures even without naming them.

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 final sentence, 'Use to browse a specific European health data collection,' gives clear contextual guidance. However, it does not explicitly state when not to use the tool or name alternative siblings for cases like cross-dataset search, so it lacks exclusions.

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