list_files

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

With no annotations provided, the description must disclose behavior on its own. It clearly indicates this is a read-only listing operation and describes the return format (list of dictionaries with name, size, type, path). However, it does not mention edge cases like permission errors, sorting, recursion, or whether paths are absolute/relative.

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 well-structured with Args, Returns, and Example sections. Every sentence adds value: parameter explanations, return type, and practical usage examples. It is appropriately sized for the tool's complexity without redundant repetition of the schema.

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, all-optional-parameter listing tool, the description is largely complete. It documents all parameters, return values, and provides two examples. However, it lacks explicit usage guidance or exclusions (e.g., when to prefer find_duplicates), and it does not mention potential errors, which slightly limits completeness.

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?

Schema description coverage is 0%, so the description carries the full burden. It explains each parameter with meaningful detail beyond the schema: 'directory' defaults to current directory, 'pattern' shows example glob patterns, and 'include_hidden' controls hidden file visibility. The examples further clarify parameter usage.

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 is specific: 'List files in a specified directory with optional filtering.' This clearly states the verb (list), resource (files in a directory), and scope (optional filtering). It also distinguishes itself from sibling tools focused on duplicates (find_duplicates, delete_duplicates) by focusing on basic file listing.

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 examples like list_files(directory='.', pattern='*.py') and parameter explanations, but it never explicitly states when to choose this tool over alternatives. There is no mention of when not to use it or how it relates to the sibling duplicate-related tools.

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