create_directory

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

Annotations already establish readOnlyHint=false and destructiveHint=false; the description goes further by disclosing recursive creation ('multiple nested directories in one operation'), the sandbox boundary, and automatic path normalization. It still omits what happens on failure or what the call returns, keeping it short of a 5.

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 core statements are front-loaded and clear, but the path paragraph is redundant — it asserts 'Absolute paths are the most reliable' and then repeats 'Absolute paths are generally the most reliable' a few lines later. The trailing 'DC: ...' branding sentence consumes space without adding selection or invocation value.

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 mutation tool with no output schema, the description covers the essentials: recursion behavior, sandbox restriction, and path handling. The absence of any statement about the return value or error behavior is a minor gap given there is no output schema.

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 single path parameter has 0% schema description coverage, so the description must compensate, and it does: absolute vs relative behavior, tilde-path caveats, slash-direction normalization, and cwd dependence. The only gap is that it never says whether the path is a file or directory target beyond the tool's own purpose.

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?

States a specific verb and resource ('Create a new directory') and adds a meaningful nuance ('or ensure a directory exists') that signals idempotent behavior. It does not name any sibling, but unlike list_directory or move_file the action is unambiguous from the text alone.

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 gives a real constraint ('Only works within allowed directories') and path-format advice, which implies suitable contexts, but it never states when to prefer this tool over alternatives such as write_file creating parent paths, nor does it name any sibling. Usage is inferable rather than explicit.

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