list_files

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

Annotations already declare readOnlyHint, destructiveHint=false, idempotentHint, and closed-world scope, so the safety profile needs no restating. The description still adds real value with the 1,500-entry cap and the non-recursive 'immediate' scope, which are not in the annotations; it just doesn't say what happens when the cap is exceeded.

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?

Three short sentences, front-loaded with the core action and scope, then the sibling routing, then the safety note. Every sentence carries distinct information with no repetition.

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?

With no output schema, the description usefully enumerates the returned fields and the entry cap, which is most of what an agent needs. The only gap is truncation behavior past 1,500 entries, which matters for a listing tool but is a minor omission overall.

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 coverage is 100%, so both 'root' and 'path' are already documented with defaults and meanings. The description's word 'immediate' reinforces that the listing is non-recursive, but adds no path syntax or root-selection guidance beyond what the schema provides, making the baseline 3 correct.

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 opens with a specific verb and resource (list immediate files and directories) and states the scope limits precisely: non-recursive, an approved root, capped at 1,500 entries. It also names the returned fields (relative path, type, size, modification time), so an agent knows exactly what this produces versus search_files.

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?

It explicitly names the alternative, 'search_files for recursive discovery,' which is the key decision point for choosing between the two. The closing 'Does not change files' further signals this is a safe read for inspection-style tasks rather than mutation workflows.

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