List local data files

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

The annotations already declare readOnlyHint=true and openWorldHint=false, so the description does not need to cover the read-only or local nature. It adds useful behavioral context by stating that only tabular formats are returned and that output includes file sizes. It does not discuss subtle behaviors like hidden files, sorted order, or invalid-directory errors, but the annotation coverage lowers the bar.

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 a single front-loaded sentence that puts the action, target, and output detail first, then packs the format list into a clean parenthetical. There is no filler or redundancy.

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 with only two well-documented parameters and read-only annotations, the description is nearly complete. It tells the agent what is returned (tabular data files with sizes) and the supported formats. Minor omissions, such as default behavior for 'recursive' and error handling for nonexistent directories, do not significantly hamper correct usage.

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 input schema has 100% coverage for both parameters: 'dir' and 'recursive' are each described. The description adds some context by specifying 'local' and listing supported file formats, but it does not add meaningful parameter-level details beyond the schema. Baseline 3 applies.

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 names a specific action ('List') and a precise resource ('tabular data files CSV/TSV/JSON/NDJSON/Parquet/Excel in a local directory'), and adds the output detail 'with sizes'. This clearly distinguishes it from sibling tools like preview_data, describe_data, and query_data, which operate on the file contents rather than listing 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?

There is no explicit when-to-use or when-not-to-use guidance relative to the siblings. However, the description strongly implies this is the discovery step before analyzing or previewing data files. Clear alternative guidance would improve selection reliability.

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