list_directory

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

No annotations are provided, so the description carries the full burden. It discloses a genuine side effect ('Resets idle timer') and the read-only nature of 'List'. However, it omits return format, recursion depth, and handling of hidden files, which are relevant behavioral details.

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 three sentences, each serving a distinct purpose: the primary action, path semantics, and a prerequisite plus side effect. No redundant words or filler, making it highly concise and well-structured.

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 one-optional-parameter listing tool with no output schema, the description covers the essentials: what is listed, path relativity, and a required precursor. It lacks explicit mention of recursion or return structure, but these are minor given the tool's simplicity.

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 schema has 100% description coverage for the single 'path' parameter, with a description mirroring the tool's textual explanation. The description adds no extra parameter semantics beyond the schema, so baseline 3 is appropriate.

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 files and directories') and scope ('in the cloned repo') with a specific verb+resource structure. It distinguishes itself from sibling tools like read_file (which reads file content) and search_repo (which searches), making the purpose unambiguous.

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 explicitly instructs 'Call ensure_repo first', providing a clear precondition for use. It also implies the tool is for initial exploration of the repo structure, naturally contrasting with alternatives like read_file or search_repo. However, it doesn't explicitly mention 'when not to use', so it stops short of a perfect score.

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