MCP Server Framework

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the return value but doesn't describe key behaviors such as whether this requires specific permissions, if it's a read-only operation, potential rate limits, or what 'configured allowed paths' entails in practice. This leaves significant gaps for a tool that interacts with file system security settings.

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 concise and well-structured with two sentences: one stating the purpose and another describing the return value. It's front-loaded with the main function and avoids unnecessary details. A perfect score is reserved for exceptional cases, but this is efficiently written.

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 there's an output schema (which handles return values), 0 parameters, and no annotations, the description is minimally complete. It states what the tool does and hints at the return, but for a tool dealing with file system paths (a potentially sensitive area), more context on behavior and usage would be beneficial to fully inform the agent.

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 0 parameters, and the input schema has 100% description coverage (though empty). The description doesn't need to explain any parameters, which is appropriate. It could potentially mention why no parameters are needed, but this isn't required for a high score given the lack 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 the tool's purpose with a specific verb ('Get') and resource ('list of allowed file system paths'), making it immediately understandable. However, it doesn't differentiate this tool from sibling tools like 'list_directory' or 'get_file_info', which also retrieve file system information, so it doesn't achieve the highest score.

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 provides no guidance on when to use this tool versus alternatives. With sibling tools like 'list_directory' and 'get_file_info' that also interact with the file system, there's no indication of when this tool is preferred or what specific use cases it addresses, leaving the agent without contextual usage information.

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