Save to YouTube Knowledge Library

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

The description discloses important behavioral beyond annotations: it overwrites existing content of the same type for the same video, and it returns the saved file path. This adds context not covered by the idempotentHint or destructiveHint annotations, which is valuable for the agent.

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 two sentences, front-loaded with the primary purpose, and includes key behavioral facts without any fluff. Every sentence earns its place, making it highly concise and well-structured.

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 6-parameter schema and no output schema, the description adequately covers purpose, overwrite behavior, and return value. It does not explain the library concept or parameter relationships beyond that, but the schema fills in those details, leaving the description contextually complete for a straightforward save operation.

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%, so the baseline is 3. The description does not add significant parameter-specific meaning; 'summary or skill note' aligns with the contentType enum but does not elaborate on parameter formats or values beyond what the schema already provides.

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 tool's function with a specific verb and resource: 'Save a summary or skill note to the local YouTube knowledge library.' It also distinguishes itself from sibling tools by focusing on writing to the library, whereas most siblings are read-oriented.

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 does not explicitly specify when to use this tool versus alternatives, but the context of sibling tools like list_library implies its role as the write counterpart. The overwrite note hints at usage constraints but lacks explicit exclusions or alternative tool references.

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