ls

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

The description discloses skip patterns and return format, which is helpful. However, it mentions a 'stat=true' parameter that is not defined in the input schema, creating a contradiction that reduces trust in the tool's actual behavior.

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 two sentences and efficiently covers purpose, return format, and skip rules. The mention of an undocumented parameter slightly detracts but overall it is well-structured and concise.

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 listing tool, the return format is described, but the meaning of 'n,d,s' is not explained. The missing parameter 'stat' and lack of clarification on its intended use leave the description incomplete.

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 has zero parameters with 100% coverage, so baseline is 4. The description references a 'stat' parameter not in schema, which adds confusion rather than value. It does not clarify the actual (non-existent) 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 lists a directory and specifies return format and skip patterns. However, the mention of 'stat=true' implies a parameter not present in the schema, which slightly muddles clarity.

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?

No guidance on when to use ls versus sibling tools like read_file or search. The description does not provide context for appropriate usage or mention alternatives.

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