get_youtube_contact

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

No annotations are provided, so the description must carry the burden. It discloses the credit cost and the specific input format requirement, but does not reveal whether the operation is read-only, any potential rate limits, or what happens if the channel has no contact info.

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 consists of two short sentences that efficiently convey the purpose, input restriction, and cost. No unnecessary words, and the critical information is front-loaded.

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 no annotations and no output schema, the description provides basic purpose and input constraints but does not explain the output structure (e.g., what 'for business + public' means in practice). It is adequate for a simple tool but leaves some context gaps.

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 coverage is 100% with one parameter fully described in the schema. The description adds value by clarifying that only the immutable UC form is accepted and explicitly listing rejected URL types (@handle, /c/vanity, /user/legacy), which is beyond the schema's generic description.

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 it retrieves contact email addresses for a YouTube creator, specifying both 'for business' and public emails. The verb 'Get' and resource 'YouTube creator's contact email addresses' are precise, and it distinguishes from other YouTube tools by focusing on contact info.

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 mentions credit cost and the input constraint (only UC channel ID accepted, not handles or vanity URLs), providing some guidance on when to use. However, it does not explicitly state when to use this tool versus alternatives or when not to use it.

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