assets_sign

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

With no annotations, the description carries the full burden. It discloses the time-bound nature, default TTL (1 hour), maximum (7 days), and that it is a presigned GET URL (read-only). It doesn't specify error behavior if blob is missing, but the key behavioral traits are covered.

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 concise sentences: the first states the core functionality, the second provides usage guidance and default/max values. No wasted words, front-loaded with essential information.

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 simple 3-parameter tool with no output schema, the description is largely complete. It explains purpose, usage, and key parameter constraints. It could mention that the URL is returned, but that is implied by 'generate... URL'.

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% with parameter descriptions. The description adds context about default TTL and max TTL, but this is already partially covered in the schema. Baseline 3 is appropriate as the description adds marginal value beyond 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-boxed S3 presigned GET URL for a blob, with a specific use case (external sharing without exposing API key). It distinguishes itself from sibling assets tools like assets_get, assets_ls, etc.

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 says to use this for sharing private blobs externally without exposing the apikey. It provides clear context but does not explicitly exclude cases where alternative tools (e.g., assets_get) might be more appropriate.

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