list-i18n-regions

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

With no annotations, the description carries the transparency burden. It discloses the read-only nature ('List') and a quota cost ('1 quota unit per call'), which is useful. However, it omits auth requirements and any mention of pagination or output format, though the zero-parameter nature reduces risk.

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 exactly two concise sentences with no filler. It states the purpose and the cost, both essential, and nothing more.

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?

The tool is trivial (no parameters, no output schema), and the description covers the core purpose and a key cost detail. It is adequate for an agent to invoke correctly, though it does not differentiate from sibling list tools or describe the response structure.

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 zero parameters, so the baseline is 4. The description adds no parameter-level meaning because there are none to describe, but this is not a deficiency given the schema covers everything.

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 'List the content regions supported by YouTube' with a specific verb and resource. It distinguishes from sibling list-i18n-languages by focusing on regions rather than languages.

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 use when needing YouTube's supported content regions, but lacks explicit guidance on when to use this tool versus alternatives like list-i18n-languages or list-video-categories. No alternative tools are mentioned.

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