list_files

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

With no annotations, the description carries the behavioral burden. It usefully discloses the default path and that entries include type and size, and 'List' implies a non-destructive read. However, it does not explain edge behaviors such as hidden files, path traversal limits, or errors for nonexistent directories.

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?

Two tight sentences front-load the core action and output, then add the default path and a practical usage tip. Every word earns its place with no 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, the description covers purpose, scope, default path, and output fields, which is sufficient for most calls. It lacks detail on error cases and path resolution behavior, but those are minor for this tool's complexity.

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 50%: path is documented with a default, but sandbox_id has no description. The tool description adds context by defining the scope as a sandbox directory, which implies sandbox_id identifies the sandbox, but it does not fully compensate for the missing sandbox_id semantics.

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 the contents of a directory'), the resource ('in a sandbox'), and the output details ('type and size of each entry'). This clearly distinguishes it from siblings like read_file, write_file, and run_command.

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?

'Use this to find what your code produced before reading it' gives clear practical context for when to call this tool. It does not explicitly name alternatives or exclusions, but the usage intent is unambiguous enough.

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