fs__create_directory

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

Discloses idempotent behavior (silent if exists), nested creation, and allowed directories. Lacks permission or failure details, which is acceptable for a simple creation tool.

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 sentences, front-loaded with primary action. No 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?

Fully covers tool use case, behavior, and constraints. No output schema needed; return value is implicit.

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?

Only parameter 'path' is described in context (nested creation, path within allowed dirs). Adds meaning beyond schema, which only specifies type 'string'.

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?

Description clearly states verb 'create' and resource 'directory', includes details like nested creation and silent success. Distinguishes from file-writing siblings.

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 use case ('setting up directory structures') and constraint ('only within allowed directories'). No negative guidance or sibling alternatives, but context is clear.

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