list_directory

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

Beyond the readOnlyHint annotation, the description adds behavior details about sorting (sortBy values and their effects) and the reverse option, giving the agent a better sense of the tool's output ordering. It also notes the default pattern '*', which is useful context.

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 sentence that packs essential parameter details without fluff. It is front-loaded with the primary purpose and wastes no words.

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 4-parameter read-only directory listing tool with an output schema, the description covers purpose, filtering, sorting, and defaults. Output format is handled by the output schema, so no gap exists.

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 schema has no parameter descriptions, but the description compensates fully by explaining path (required), pattern (optional, default *), sortBy (with specific sort options), and reverse (flips order). This adds substantial meaning beyond the raw 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 clearly states the tool lists files and directories with optional glob filtering, using the verb 'List' and specifying the resource. This distinguishes it from sibling tools like 'tree' (which implies hierarchy) and 'search_files' (which implies content search).

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 usage context by explaining the parameters, including the default sort order and reverse flag. However, it does not explicitly compare to alternatives like 'tree' or 'search_files' for when to choose this tool.

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