list_country_groups

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

Annotations (readOnlyHint, openWorldHint) indicate basic safety, and the description confirms a listing operation. However, the mention of filtering by region/income is inconsistent with the parameterless schema, potentially confusing behavior. No additional behavioral traits disclosed.

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 single-sentence description is concise, but the phrase 'by region and World Bank income class' is misleading given the empty parameter set. It earns its place but introduces inaccuracy.

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 parameters and an output schema present, the description minimally covers purpose. It lacks context about how the output relates to sibling tools or how to use the returned groups. Some detail is missing for full completeness.

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?

No parameters exist (schema coverage 100%), so the description adds value by explaining the tool's purpose (listing groupings by region and income class). This contextualizes what the tool returns beyond the name.

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 clearly states the tool lists GHED country grouping values, with a specific scope ('by region and World Bank income class'). However, this implies filtering parameters that do not exist in the input schema, creating a slight mismatch.

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?

No guidance on when to use this tool versus siblings like list_curated_country_groups or summarize_country_group. The description does not specify context or alternatives.

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