mkdir

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

Annotations already indicate destructive behavior (destructiveHint=true). The description adds valuable behavioral context by specifying that it creates only 'one new directory level' (non-recursive), which is a key constraint, and details the blocked paths. This goes beyond the annotation without contradicting it, although it omits edge-case behavior like what happens if the directory already exists.

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 concise, with two sentences that front-load the core purpose and then provide necessary constraints. Every word adds value, and there is no redundant or filler content.

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?

The description covers the tool's main purpose, preconditions, and restrictions, but it lacks important context for a complete understanding: there is no explanation of the return value (no output schema), no clarification of what constitutes an 'active Direct session,' and no mention of the review_id parameter. For a simple tool like mkdir, this is moderately incomplete but not severely so.

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 description does not compensate. It implies the 'path' parameter and 'session_id' via context, but the 'review_id' parameter is completely unexplained. For an agent to invoke the tool correctly, it needs to know the purpose of each parameter, especially review_id, which is not obvious from the name or context.

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 function with a specific verb ('Create'), resource ('directory level'), and scope ('inside an active Direct session'). It distinguishes itself from sibling file operations like create_file and move_file by focusing solely on directory creation, and the word 'new' clarifies it does not modify existing directories.

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 clear usage context: it operates within an active Direct session, requires parent directories to already exist, and explicitly lists blocked path categories. While it does not name alternative tools directly, the exclusions and prerequisites effectively guide when to use this tool versus creating files or touching restricted paths.

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