list_directory

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

With no annotations provided, the description carries the full burden. It discloses the exact return structure ('dict with two keys'), the behavior for empty paths (list root), and the formatting of directory names (no trailing slash). It does not discuss error handling or permission issues, but for a simple listing operation, this is adequate.

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 well-structured with distinct sections for purpose, server context, arguments, and return value. Each part serves a purpose: the top-level directory examples help the agent form valid paths, and the return format avoids ambiguity. It is informative without being verbose.

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 one optional parameter and an output schema present, the description is complete. It covers the root listing behavior, provides example paths, and explains the return value structure. No critical operational details are missing for the agent to invoke it correctly.

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 0% because the input schema lacks descriptions. The description compensates fully by explaining the 'path' parameter with examples ('json/', 'json/goes/') and specifying that empty string lists the root. This adds significant meaning beyond the bare schema.

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 states a specific action ('List files and subdirectories at a path') on a specific resource (the SWPC data server). It distinguishes itself from siblings like fetch_file, which retrieves file contents, and list_products, which lists products rather than arbitrary directory contents.

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 on when to use the tool: browsing the server's file tree, with examples of top-level directories and path formats. It doesn't explicitly name alternative tools or exclusions, but the usage context is unambiguous enough for an agent to distinguish this from file-fetching or product-listing tools.

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