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 discloses that only readable files are included and that traversal is recursive, but it does not describe output format, handling of directories, permission errors, or invalid subdirectory paths.

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 four words and front-loaded: it states the action, resource, filter, and recursion mode with no filler. Every word earns its place.

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 one-parameter tool, the description gives enough to understand the core operation, but with no output schema and no sibling differentiation, an agent is left without guidance on return format, error cases, or when to prefer this over read_file or search.

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% for the single optional subdirectory parameter, so the schema documents the parameter's meaning and default behavior. The description itself adds no parameter detail, but the baseline of 3 applies because the schema already covers the parameter 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 uses a specific verb ('List') and resource ('files'), and adds the recursive scope, making the tool's basic purpose clear. It does not explicitly differentiate from siblings read_file and search, though listing files is naturally distinct from reading or searching.

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 guidance on when to use this tool versus read_file or search. No context, prerequisites, or exclusions are provided, leaving the agent to infer appropriate usage from the tool name alone.

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