list_libraries

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the description adds value by explaining the behavioral context of the detail flag (exposing .SUBCKT and .MODEL names). This helps the agent understand the tool's non-destructive, read-only nature beyond the 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?

The description is two sentences long, front-loaded with the core purpose, and every sentence adds value. No filler or redundant information.

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 presence of an output schema (return values documented elsewhere) and comprehensive annotations, the description covers the essential behavior of listing libraries and the detail feature. It does not discuss pagination or the path filter, but those are already present in the schema, so the description is complete for its role.

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?

With 100% schema coverage, the baseline is 3. The description adds meaningful context for the detail parameter by providing a concrete use case example (foundry .bjt/.mod files with hundreds of .MODEL cards), which clarifies why one might use it and what benefit it 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 'List loaded libraries' with a specific verb and resource, and highlights the optional detail flag to show .SUBCKT and .MODEL names. It distinguishes itself from sibling tools like load_library and unload_library by focusing on listing rather than modification.

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 implies using this tool to discover loaded libraries and internal models, but does not explicitly state when to use it versus alternatives (e.g., find_model). It lacks explicit when-not or exclusion guidelines, so it meets only a minimal standard.

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