source.add

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

Annotations already indicate readOnlyHint=false and openWorldHint=true; description adds that the source is 'processed and indexed', which provides marginal extra behavior context. No contradiction, but lacks details on side effects like processing time or error states.

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?

Description is front-loaded with the main purpose and uses a bullet list for source types, making it scannable. However, the list partially duplicates the schema enum, and could be slightly more concise.

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 complexity (7 parameters, 1 required) and presence of an output schema, the description adequately covers purpose, supported types, and processing. It does not mention prerequisites or error scenarios, but is sufficient for a typical add 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?

Description adds value beyond the 100% schema-covered parameters by grouping source types and stating which parameter is required for each type (e.g., file_path for 'file'), improving understanding of parameter dependencies.

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?

Description clearly states the verb 'Add' and resource 'source to the current NotebookLM notebook', and lists supported source types (file, url, text, youtube, google_drive), distinguishing it from sibling tools like source.delete.

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?

Description implies usage context (adding different source types) but does not explicitly state when to use this tool versus alternatives (e.g., library.add or content.generate), nor provides exclusion criteria.

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