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

With no annotations, the description carries the transparency burden. It explicitly discloses idempotent behavior ('如果路径已经存在, 直接返回该文件夹元数据') and compares to mkdir -p for recursive creation. It does not detail permission requirements or edge-case errors, but the core mutation behavior and return-on-existing behavior are transparent.

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: two short sentences, front-loaded with the action and an analogy, followed by a crucial idempotency note. Every word contributes value, and there is no redundancy with the schema.

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 create-folder tool with no output schema, the description provides the essential behavioral context: recursive mkdir -p-style creation and idempotent return. The normal-case return metadata is only implied, and error conditions are not discussed, but these are minor gaps given the tool's simplicity.

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 schema already documents the single parameter with full detail, including path format and mkdir -p semantics, so description-level parameter clarification is unnecessary. The tool description adds the idempotency note, which is behavioral rather than parameter-specific. Per rubric, high schema coverage establishes a baseline of 3.

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 opens with '创建文件夹' and the mkdir -p analogy, making the action and resource unmistakable. It is unique among the sibling tools (the only folder-creation tool), so there is clear differentiation. The verb+resource specificity is strong.

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 mkdir -p analogy and idempotency statement give clear context for when to use the tool: create a folder recursively and safely even if the path already exists. It does not explicitly list when-not scenarios, but no alternative create-folder tool exists in the sibling list, so the guidance is sufficient.

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