get_presigned_url

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

With no annotations, the description carries the full burden. It discloses that links are time-limited and support GET/PUT, but omits key behavioral details: required permissions, whether the object must exist, default method/expiry behavior, and whether generating a URL has side effects.

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?

A single, front-loaded sentence with no wasted words. It efficiently communicates the core action, time limitation, and supported methods.

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 four undocumented parameters, no annotations, and no output schema, a one-line description is insufficient. It lacks usage guidance, parameter semantics, and behavioral details needed to call the tool correctly.

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% across four parameters. The description conceptually covers method (GET/PUT) and expiry ('时效'), but says nothing about the required key, the optional bucket, expiry units/defaults/limits, or how those parameters interact.

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 states a specific verb and resource: generating a time-limited presigned HTTP(S) direct link, with supported methods GET/PUT. It is distinguishable from transfer siblings like download_file and upload_file, though it does not explicitly name or contrast them.

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?

Usage is implied: use this when you need a time-limited direct link for GET download or PUT upload. However, it provides no explicit when-to-use guidance, no exclusions, and does not point to alternatives such as download_file or upload_file.

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