Create Directory

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

Annotation idempotentHint=true is echoed by 'will succeed silently', but the description adds genuinely new behavioral facts: nested directories are created in one call, and the operation is confined to allowed directories. The sandbox constraint is real context beyond the annotations, though error behavior outside allowed dirs is not spelled out.

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 critical behavior (create-or-ensure, nested, silent success) is front-loaded in the first three sentences. The 'Perfect for...' sentence leans promotional but does carry a use case, so it mostly 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 one-parameter tool with no output schema and annotations covering the safety profile, the description covers idempotency, nesting, and the allowed-directory constraint. Only the path format and failure behavior are left unstated.

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 description coverage is 0% and the single 'path' parameter is undocumented. The description implies the path must live within allowed directories but never specifies format (absolute vs relative), so it fails to compensate for the coverage gap.

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 verb and resource ('Create a new directory') and adds a distinguishing behavior ('ensure a directory exists'), which separates it from a plain create. It does not, however, differentiate itself from siblings like list_directory or directory_tree, so a 4 rather than a 5.

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?

It offers use-case hints ('setting up directory structures for projects or ensuring required paths exist'), which imply when the tool is appropriate. It gives no explicit exclusions or named alternatives, so usage remains inferred rather than stated.

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