List Regions

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

Annotations already declare readOnlyHint=true and idempotentHint=true, fully disclosing safety and idempotency. The description adds context (controlled vocabulary, examples) but no additional behavioral traits beyond what annotations provide.

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, clear sentence that conveys the essential purpose without any extraneous words. It is front-loaded with the action ('List') and subject ('controlled region vocabulary').

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 zero parameters, complete annotations, and an existing output schema, the description provides sufficient context. It explains the purpose and gives examples, making it complete for a simple list tool.

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?

There are zero parameters, so the schema coverage is 100% and the description does not need to explain parameters. Baseline score of 4 is appropriate as the description adds no redundant param info.

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 identifies the tool as listing the controlled region vocabulary for the provider registry, with concrete examples ('us', 'eu', 'uk', 'global'). It distinguishes itself from sibling tools like opendata_domains_list which likely lists domains, not regions.

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 implies when to use the tool: when needing the list of allowed region values. It does not explicitly state when not to use it or mention alternatives, but given the simplicity and lack of parameters, the guidance is adequate.

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