list_data_libraries

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

No annotations, so description must carry full burden. It discloses that entries include key, title, size, URL, and file name, which tells the agent what it gets. However, no info on filtering, pagination, or return format beyond that. Output schema exists, so return format is partly covered.

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 tight sentences, front-loaded with the core action and scope. Every word earns its place.

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-param list tool with an existing output schema, the description is complete: it states what is listed and what each entry contains, which is sufficient for correct invocation.

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?

No parameters, so baseline 4. The description correctly implies no input is required and provides context about what the output contains.

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?

Specific verb+resource: 'List the official VTT Serpent nuclear data libraries that can be downloaded'. It enumerates examples and names the sibling (download_data_library) implicitly by contrasting available vs downloadable libraries.

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?

Clear context – this tool surfaces libraries that can be downloaded, while download_data_library performs the download. No explicit when-not-to-use or exclusions, but the purpose is unambiguous.

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