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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the description does not need to restate safety. The description adds that it returns a list, which is expected, but provides no further behavioral context (e.g., pagination, permissions). Adequate given annotations.

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?

Two sentences, front-loaded with the core purpose, and a separate line for bulk support. No unnecessary words, highly efficient.

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?

The description covers purpose and bulk support, but lacks details about return fields beyond id and title (the '...' is vague), and does not mention notebook_id requirement explicitly. With no output schema, more detail on the return structure would improve completeness.

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 descriptions are absent (0% coverage). The description implicitly references notebook_id and introduces notebook_ids for bulk support, but does not explain parameter formats, constraints, or relationships. Partially compensates but insufficient for a 2-parameter tool with no schema descriptions.

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 lists sources of a notebook and returns an array of objects with id, title, and presumably other fields. This distinguishes it from sibling tools like notebooklm_source_get (single source) and notebooklm_source_add/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?

The description mentions bulk support via notebook_ids, implying batch usage, but does not explicitly guide when to use this tool versus alternatives like notebooklm_source_get or when not to use it. Context is implied but not explicit.

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