Request Upload URL

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

Without annotations, description discloses key behaviors: short-lived presigned URL, PUT requirement with same Content-Type, expiry time. Could note error states but adequate.

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 fluff, logically structured steps. Every sentence adds value.

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, but description explains return type (presigned URL) and next step. Could specify exact return format but sufficient for the tool's simplicity.

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; description adds context: filename as suffix, fileSize max 1.9GB, contentType must match PUT. Adds value beyond 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?

Description clearly identifies the tool as 'Step 1 of the direct-upload flow' returning a presigned URL, distinguishing it from sibling tools like 'confirm_upload'.

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?

Description explains the workflow (this step, then PUT, then confirm_upload) and mentions the URL expiry (~15 min), giving clear usage context.

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