延长保留时间

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

The annotations already indicate a mutating, non-destructive, idempotent operation. The description adds valuable behavioral specifics: the expiry is recalculated from 'now', and there is a hard limit of 720 hours. This goes beyond the annotations and clarifies the operation's semantics.

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, well-structured sentence that immediately conveys the core behavior. It is succinct with no redundant wording, making it easy to parse quickly.

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 tool with two parameters and no output schema, the description covers the essential behavior and constraints. It does not mention return values or error handling, but given the annotations and schema coverage, it is sufficiently complete for an agent to understand when and how to invoke it.

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?

While the schema provides full descriptions for both parameters, the description enhances understanding by clarifying that hours are relative to 'now' and specifying the 720-hour upper bound, which the schema does not include. This adds semantic meaning beyond the formal schema.

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 purpose: recalculate a file's expiration time to be retained for N hours from now, with a 720-hour cap. It uses a specific verb (recalculate/extend) and resource (file expiry), distinguishing it from siblings like delete_file or sweep_expired.

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 does not explicitly specify when to use this tool versus alternatives. It explains what it does but lacks context like 'Use this when you need to keep a file longer' or exclusions (e.g., instead of delete_file). No when-not-to-use guidance is provided.

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