lib_list_libraries

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

With no annotations, the description carries the burden. It discloses the read-only nature ('List') and adds the qualifier 'configured', implying only loaded libraries are returned. However, it does not detail whether symbol and footprint libraries are returned together or separately, nor any other behavioral nuances. The description is acceptable but not rich.

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 a single short sentence that is front-loaded with the verb and object. It contains no fluff or redundant information, making it highly concise and well-structured.

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 simple list tool with no parameters and an output schema present, the description sufficiently explains its purpose. It conveys the scope (configured libraries) and the object type (symbol and footprint), which is complete for an agent to select and invoke the tool correctly.

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 has zero parameters, and the schema has no properties. According to the rubric, a baseline of 4 applies for 0-param tools. The description correctly says 'configured' libraries, which adds slight context, but there are no parameter details to add since none exist.

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 action ('List') and the resource ('configured symbol and footprint libraries'), making it distinct from sibling tools like lib_list_footprints which likely lists individual footprints within a library. The verb and resource are specific and unambiguous.

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 usage through its name and one-liner, but does not explicitly state when to choose this over alternatives such as lib_list_footprints or lib_search_footprints. No exclusions or alternative guidance is provided, so it falls short of a clear context.

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