mkdir

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

While the description aligns with the destructiveHint annotation, it incorrectly claims a 'mode' parameter that is not in the schema, potentially misleading agents about available capabilities.

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?

Front-loaded with key purpose, then details. Well-structured with bullet-like sentences, though slightly verbose with redundant phrases like 'Use to create directory structures'.

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?

Mentions JSON output and safe failure, but the erroneous mode parameter and lack of output schema limit completeness for a tool with 4 input parameters.

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% with parameter descriptions, but the description adds value for existing parameters (dry_run, parents, exist_ok). However, it falsely introduces a 'mode' parameter not in the schema, reducing reliability.

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 creates directories, with specific features like parent-directory creation and dry-run support. It distinguishes from siblings by explicitly mentioning alternatives for removal and temporary directories.

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?

Provides explicit when-to-use (creating directory structures) and when-not-to-use (use rmdir/rm for removal, mktemp for temp dirs). Mentions specific sibling tools for context.

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