create_directory

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

With no annotations provided, the description carries the full burden and adds valuable behavioral context: it explains that the tool can create nested directories, works only within allowed directories, normalizes paths automatically, and has path reliability considerations (absolute vs. relative/tilde). This goes beyond basic purpose to describe operational traits.

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 front-loaded with the core purpose but includes verbose path instructions and meta-commentary about command referencing ('DC: ...'), which adds clutter. Some sentences (e.g., the referencing note) don't earn their place for tool selection, reducing efficiency.

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 no annotations, 0% schema coverage, and no output schema, the description does a solid job covering key aspects: purpose, behavioral constraints (allowed directories, path handling), and parameter guidance. It lacks details on error cases or return values, but for a single-parameter tool, it's reasonably complete.

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 input schema has 0% description coverage for its single parameter 'path', but the description compensates well by explaining path semantics: it must be absolute for reliability, is automatically normalized, and relative/tilde paths may fail. This adds meaningful context beyond the bare schema 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?

The description clearly states the tool's purpose: 'Create a new directory or ensure a directory exists.' It specifies the verb ('create'/'ensure') and resource ('directory'), though it doesn't explicitly differentiate from siblings like 'list_directory' or 'move_file'. The mention of creating nested directories adds specificity.

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 implied usage guidance by stating 'Only works within allowed directories' and emphasizing absolute paths for reliability. However, it doesn't explicitly say when to use this tool versus alternatives (e.g., vs. 'move_file' for directory manipulation) or list any exclusions, leaving some context gaps.

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