list_libraries

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

The readOnlyHint annotation already establishes this as a safe read operation, and the description aligns with that. It adds meaningful behavioral nuance by distinguishing between what SAS considers read-only and what the server policy permits writing to, which is valuable context 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?

A single, well-structured sentence communicates the action, resource, and returned fields without unnecessary words. The key verb and resource are front-loaded, making the description scannable and 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?

Given that the tool is parameterless, has an output schema, and is annotated as read-only, the description provides sufficient context for correct invocation. The mention of assigned libraries and policy details helps the agent understand the scope and semantics without needing additional explanation.

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, so there are no parameter semantics to clarify. The description appropriately focuses on what the tool returns rather than on inputs, and no parameter documentation burden exists.

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 that the tool lists assigned SAS libraries and enumerates the specific attributes returned: path, engine, SAS read-only status, and server policy write access. This is a specific verb+resource combination that distinguishes it from sibling tools like list_datasets, which operate on datasets rather than 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?

The description makes the tool's purpose clear, so an agent can infer it is appropriate when needing an overview of available libraries. However, it does not explicitly mention when not to use it or contrast it with sibling tools such as list_datasets or describe_dataset, leaving usage boundaries implied rather than stated.

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