list-video-categories

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

No annotations are provided, so the description carries the full burden. It discloses the quota cost ('Costs 1 quota unit per call') and the 'assignable' nature of the categories, which adds useful context. However, it does not mention response format, permissions, or whether the operation is read-only (though 'list' implies it).

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, front-loaded sentence with no wasted words. It conveys the action, resource, scope, and a key cost detail efficiently.

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?

For a simple list tool with one optional parameter and no output schema, the description is adequate but does not specify the return structure, pagination, or sorting. Given the low complexity, the missing details are unlikely to hinder correct invocation, but the description could be slightly more 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%—regionCode is fully documented with a clear description and default value. The description's phrase 'for a region' loosely references the parameter but adds no new semantic detail beyond the schema. Baseline 3 is appropriate since the schema handles parameter explanation.

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 'List assignable video categories for a region' clearly states a specific verb and resource, distinguishing it from sibling tools like list-channels and list-videos. The scope ('for a region') aligns with the regionCode parameter, making the tool's purpose unambiguous.

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 usage—when you need video categories for a region—but does not explicitly state when to use it over alternatives or mention any exclusions. No competing category-listing tool exists among siblings, but the guidance remains implied rather than explicit.

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