fs_list

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is clear. The description adds useful behavioral context beyond annotations by specifying that the return includes entry names and metadata but never file snippets, helping agents avoid misusing the tool for content retrieval.

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?

Two short sentences, front-loaded with the core action and scoped by a clarifying negative. Every word adds value, and there is no redundant restatement of schema or annotation 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?

For a read-only listing tool with robust annotations and an output schema, the description is mostly sufficient. It captures the core purpose and the key behavioral boundary (no file snippets). It does not explain distro/platform context or limit behavior, but parameter names and the structured schema partially cover that gap.

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%, and the description provides no parameter-level guidance. It only implies that the operation targets a directory via 'List directory entry names', leaving path, limit, distro, and platform semantics entirely to their names and schema types. The description must compensate for the lack of schema descriptions but does not.

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 uses a specific verb and resource ('List directory entry names and metadata') and clearly distinguishes this from sibling file tools by stating it never returns file snippets. This makes the tool's scope immediately clear and differentiates it from content-reading tools like fs_read or fs_inspect.

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 clear context that this is a directory-listing operation, and the explicit note 'never returns file snippets' gives an implicit exclusion when file content is needed. However, it does not explicitly name alternatives or provide a when-not-to-use directive, so it falls 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.