check_youtube_handle

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 tool's behavior by stating it returns information about the channel if it exists or confirms availability if it doesn't, which covers the basic outcome. However, it lacks details on error handling, rate limits, authentication needs, or response format, leaving gaps in behavioral context.

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 concise and front-loaded, consisting of two clear sentences that directly explain the tool's purpose and outcome. Every sentence adds value without redundancy, making it efficient and easy to understand.

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 low complexity (1 parameter, no output schema, no annotations), the description is reasonably complete. It explains what the tool does and the possible outcomes. However, without an output schema, it could benefit from more detail on return values, such as the structure of channel information or availability confirmation.

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 100% description coverage, with the parameter 'handle' documented as 'The YouTube handle to check (with or without @ prefix)'. The description does not add meaning beyond this, as it doesn't provide additional syntax, format details, or examples. With high schema coverage, the baseline score of 3 is appropriate.

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 specific action ('check if a YouTube channel handle is available or already taken') and the resource ('YouTube channel handle'), distinguishing it from sibling tools that check handles on other platforms like Instagram, Threads, TikTok, and X. It explicitly mentions what the tool does rather than just restating the name.

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 context by specifying it's for checking YouTube channel handles, which helps differentiate it from sibling tools that check handles on other platforms. However, it does not explicitly state when to use this tool versus alternatives or provide exclusions, such as whether it works for custom URLs or only specific handle formats.

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