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

With no annotations, the description carries the full burden of disclosing behavior. It does so well: it explains sorting order (folders by position then name, files by name), the return structure (folders[] and files[] with cuids), and the default behavior of parent_folder_id. It also warns about the feature flag and error code. It lacks only minor details like pagination or rate limits, which are not mandatory here.

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 efficient and information-dense, with no filler or repetition. Every sentence contributes to understanding the tool's purpose, output, or constraints. It is appropriately sized for the complexity of the tool.

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?

Given the absence of an output schema, the description compensates by explaining the return types (folders[] and files[] with cuids) and the gating condition. It also covers the most important behavioral aspects like sorting and navigation. The description is complete enough for an agent to select and invoke the tool correctly in most scenarios.

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 100%, so the baseline is 3. The description adds some context (passing folder id to descend, default root), but this largely duplicates the schema's existing descriptions. It does not significantly enrich parameter meaning beyond what the schema already provides.

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 the folder and file children of a Files surface (kind='files'), using the specific verb 'list' with a well-defined resource and scope. It distinguishes from sibling tools like list_surfaces (which lists surfaces) and list_recent_files (which likely lists recent files across surfaces) by focusing on immediate children and mentioning the 'files' kind.

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 for usage: it returns cuids that can be passed to get_file/delete_file, and explains how parent_folder_id is used to descend into sub-folders. It also discloses the availability gate, which is important for when the tool can be used. However, it does not explicitly name alternative tools for other list operations (e.g., list_recent_files), so it falls short of a 5.

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