List Allowed Directories

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

Annotations already declare readOnlyHint=true and openWorldHint=false, covering the safety and scoping. The description adds that subdirectories within allowed directories are also accessible, which is a useful detail. However, it doesn't disclose edge cases like what happens if no directories are configured or whether the list is static or dynamic. With annotations handling the core safety profile, this is adequate but not exceptional.

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 consists of two short sentences, each serving a clear purpose: the first defines the return value, the second provides usage guidance. There is no redundancy or unnecessary 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 tool has no parameters, has an output schema, and annotations are present, the description is complete. It explains what the tool returns, that subdirectories are included, and when to use it. No additional context is needed for effective usage.

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 the description does not need to add parameter-level semantics. The baseline score of 4 applies because there is no burden to compensate for missing schema coverage; the schema is fully covered by the absence of parameters.

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 returns the list of allowed directories and notes that subdirectories are also accessible. It uses a specific verb ('Returns') and resource ('list of directories'), and it distinguishes itself from sibling tools by focusing on the concept of 'allowed' directories rather than listing a specific path.

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 advises to use this tool to understand which directories are available before trying to access files, implying a prerequisite step. While it doesn't explicitly mention when not to use it or directly compare to alternatives, the context of sibling filesystem tools (like list_directory) makes the intended usage clear.

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