arcana_mkdir

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

No annotations are provided, and the description only says 'Create a directory'. It does not disclose what happens if the directory already exists, whether it creates intermediate parents, or any required permissions. This is insufficient for a mutation operation.

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 extremely concise: one sentence for the action and a bullet for the parameter. No redundant information, and the structure (action first, then args) is clear.

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 simple tool with one parameter and an output schema, the description covers the basics. However, it lacks details about behavior on existing directories, error handling, and requirements, which would improve completeness.

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?

With 0% schema description coverage, the description must compensate. It does so by specifying the URI format ('arcana:// URI'), which adds context beyond the raw 'string' type. However, it could be more specific (e.g., 'must end with /').

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 action ('Create a directory') and the target resource ('at a arcana:// URI'). The tool name 'arcana_mkdir' aligns perfectly, and it is distinct from siblings like 'arcana_rm' or 'arcana_ls'.

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?

No explicit guidance on when to use or not use this tool. The purpose is implied by the name and description, but there are no prerequisites, error conditions, or alternative suggestions provided.

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