blob_sign

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

Discloses key behavioral traits: time-boxed, default TTL 1 hour, max 7 days. No annotations exist, so description carries full burden. Could add that URL is read-only and requires no further auth, but current info is sufficient.

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 wasted words. Front-loads action and purpose, then adds usage guidance and constraints. Efficient and clear.

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?

No output schema, yet description does not mention what the tool returns (the signed URL). This omission may leave the agent uncertain about the response format. Otherwise adequate for a simple generation tool.

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 has 100% description coverage with clear parameter details. Description mentions TTL defaults already in schema, adding no extra meaning beyond what schema provides. Baseline score applies.

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?

Explicitly states 'Generate a time-boxed S3 presigned GET URL for a blob', clearly identifying the verb and resource. Distinguishes from sibling blob_get by emphasizing external sharing without API key exposure.

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?

Provides clear use case: share private blob externally without exposing apikey. No explicit when-not or alternatives, but context implies when direct download is needed (blob_get) or other operations.

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