s3_generate_presigned_url

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

No annotations provided, so the description carries full burden. It discloses that the URL is a bearer secret and anyone possessing it can download the object until expiry. It also mentions the dangerous guard mode requirement. Lacks details on error behavior or permissions, but overall good transparency.

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?

Two sentences, no waste. First sentence states core purpose and key characteristics; second adds critical behavioral context and usage directive. Front-loaded, every sentence 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?

Given no output schema, the description covers purpose, security implications, and usage restrictions. Lacks explicit mention of return value (the URL) but implies it. For a simple URL-generation tool, it is relatively complete.

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%, meaning all 4 parameters are described in the schema with descriptions and defaults. The description does not add extra parameter semantics beyond what the schema provides, so baseline score 3 is appropriate.

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 pre-signed URL granting read access to an S3 object. It uses a specific verb 'Generate' and resource 'pre-signed URL for S3 object', distinguishing it from sibling tools like s3_download_object or s3_copy_object.

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?

Explicitly states 'Reserved for dangerous guard mode. Confirm with the user before calling.' This tells the agent exactly when to use this tool and requires user confirmation, making usage guidelines very clear.

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