Create Directory

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

Annotations already provide idempotentHint=true (not destructive, succeeds silently if exists), and the description adds value by confirming silent success on existing directories and clarifying the nested creation behavior. No contradictions with annotations.

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?

Three concise sentences, all front-loaded with essential information. No redundancy or wasted 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?

Given the simple single-parameter tool with output schema (though not detailed in description), the description is mostly complete. It could mention the return value or output schema explicitly, but the tool's simplicity makes this less critical.

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%, so the description must compensate. It explains 'path' is the target directory (and implies acceptance of nested paths), but does not specify format (absolute vs relative) or validation details beyond 'Only works within allowed directories'. This is adequate but minimal.

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 ('Create') and resource ('directory'), clearly stating it can create a new directory or ensure it exists. It distinguishes itself from sibling tools like filesystem__write_file or filesystem__move_file by focusing solely on directory creation, and mentions nested directory support.

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 explicitly states when to use this tool (setting up directory structures, ensuring required paths exist) and notes it works only within allowed directories, providing clear context. It does not explicitly mention when NOT to use it or suggest alternatives, but given the sibling tools are mostly browser-related, the guidance is sufficient.

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