fs_list_files

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 states the tool lists files, implying a read-only operation, but doesn't specify whether it's recursive, includes hidden files, handles errors, or provides pagination. For a tool with zero annotation coverage, this leaves significant gaps in understanding its behavior beyond the basic action.

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, clear sentence that directly states the tool's purpose without unnecessary words. It's front-loaded and efficiently communicates the core functionality, making it easy for an agent to parse and understand quickly.

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 lack of annotations and output schema, the description is too minimal for a tool that interacts with a file system. It doesn't cover behavioral aspects like error handling, output format, or limitations (e.g., recursion depth), leaving the agent with incomplete context for reliable use.

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 input schema has 100% description coverage, with the 'path' parameter fully documented in the schema itself (including default value and meaning). The description doesn't add any parameter details beyond what the schema provides, so it meets the baseline score of 3 for high schema coverage without compensating value.

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 resource ('files in a directory'), making the tool's purpose immediately understandable. However, it doesn't distinguish this tool from its sibling 'fs_search_files', which might also list files but with different functionality. The description is specific about what it does but lacks sibling differentiation.

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 like 'fs_search_files' or other file-related siblings. It doesn't mention any prerequisites, exclusions, or contextual cues for selection, leaving the agent to infer usage based solely on the tool name and basic description.

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