Generate a time-limited presigned URL for an object

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

Annotations already declare readOnlyHint=true and destructiveHint=false, indicating safe read-only operation. The description adds context about credential security and time-limitation, but does not contradict annotations. It lacks detail on behavior like error handling or side effects, but suffices given the annotation coverage.

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 with two sentences. The first sentence immediately states the core action and its benefit, the second gives when to use it. Zero wasted words.

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?

Given the absence of an output schema, the description does not explain the returned URL format or how to handle responses. It adequately describes purpose and usage but leaves out details on what the agent should expect from the call, which is a moderate gap for a tool with no output schema.

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 coverage is 100%, so the baseline is 3. The description does not add significant parameter-level detail beyond what is already in the schema (e.g., operation enum, expires_in_seconds constraints). It mentions GET vs PUT and time-limited nature, but those are already clear from the 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 generates a time-limited presigned URL for a single object, specifying GET or PUT access. It explicitly distinguishes itself from scaleway_s3_get_object/put_object by noting it is intended for external sharing or large content, providing strong differentiation from sibling tools.

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 gives explicit usage guidance: it is useful for handing download/upload links outside MCP or for content too large for inline transfer via sibling tools. While it does not list explicit when-not-to-use scenarios, the context is clear and provides viable alternatives.

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