立即清理到期文件

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

Annotations already indicate destructive and idempotent behavior. The description adds valuable context that this is a manual supplement to a scheduled background task, which prevents an agent from calling it redundantly. No contradiction with annotations.

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 a single, concise sentence that is front-loaded with the purpose and immediately follows with usage context. Every word earns its place.

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 zero-parameter tool with strong annotations, the description is sufficient. It explains the purpose and when to avoid use, though it could explicitly mention that 'cleanup' implies permanent deletion of expired files, especially given the destructiveHint.

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 zero parameters and 100% schema coverage, the description appropriately adds no parameter details. The baseline of 4 is appropriate since there is no additional semantic burden to carry.

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 specific action: '手动触发一次到期清理' (manually trigger an expired-file cleanup). It distinguishes itself from all sibling tools, which focus on file operations, by targeting the cleanup task directly.

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 explicitly states when not to use it: '一般无需调用' because a background task already runs the cleanup. This gives clear guidance for an agent to avoid unnecessary invocation, though it doesn't provide alternative tool names.

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