list_regions

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It only states the basic operation without mentioning any side effects, results format, pagination, or access requirements. For a read-only list tool, this is minimal but not misleading.

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 a single 6-word sentence with no wasted words. It is appropriately sized for the tool's simplicity and fits the front-loaded expectation.

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 core functionality. However, it omits details about the output (e.g., region properties, ordering, or result limits) and does not account for potential edge cases or error states. The absence of an output schema increases the need for such information.

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 one parameter with a description, achieving 100% coverage. The description adds the insight that the filter is optional, which is not explicitly stated in the schema's 'required' field. However, it does not provide further context like the expected UUID format or behavior when no filter is given.

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 administrative regions with an optional country filter. It uses a specific verb ('list') and a clear resource ('administrative regions'). However, it does not explicitly differentiate from sibling tools like 'get_country_regions' or 'get_region', which could have overlapping functions.

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 provides no guidance on when to use this tool versus alternatives such as 'get_country_regions', 'get_region', or 'search_cities'. It lacks any context about prerequisites, limitations, or exclusion criteria.

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