List libraries

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuine value by naming the returned fields (names, descriptions, paper counts), which matters since there is no output schema, but it says nothing about authentication, pagination, or what an empty result looks like.

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 front-loaded sentences with no filler. The only slight redundancy is the "libraries/collections" synonym pair, which is defensible as ADS terminology disambiguation but marginally pads the first sentence.

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?

For a zero-argument read tool with no output schema, the description covers purpose and the shape of the return well enough to call it correctly. Minor gaps remain around whether only owned libraries or also shared/subscribed ones appear, and whether authentication is required.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline of 4 applies. The mention of paper counts is a useful hint that libraries may be empty rather than an error case.

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?

States a specific verb and resource ("List all your personal paper libraries/collections") and scopes it to the caller's own collections, which separates it from get_library_papers and create_library by name. It does not explicitly name or contrast any sibling, so it stops short of full differentiation.

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 use case (enumerate your libraries) is implied by "List all your personal paper libraries," but there is no explicit when-to-use guidance, no statement of prerequisites, and no routing to alternatives such as get_library_papers for contents or create_library for new ones.

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