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

Annotations only cover the safety profile (readOnly=false, destructive=false, openWorld=false). The description goes well beyond them: 15-minute expiry window, accepted HTTP methods (POST/PUT), the multipart 'video' field name, and the upload_id hand-off token. That is substantial operational context an agent cannot get from annotations.

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?

A single, front-loaded sentence: purpose first, then the selection condition, then the exact upload mechanics and follow-up. No filler, and every clause carries actionable 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?

There is no output schema, so the description must describe return values, and it does — upload_url, the 15-minute constraint, and upload_id — plus the downstream call. Nothing an agent needs to invoke this correctly is missing.

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?

Zero input parameters, so per the rubric the baseline is 4. The description instead supplies semantics for the produced values (upload_url, upload_id) and their consumption, which is useful but outside the input-parameter remit.

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?

Specific verb+resource: 'Mint a short-lived signed URL for uploading a video directly.' It also distinguishes its role from the sibling create-submission-tool by positioning itself as the step that produces upload_id for it, so an agent can place the tool in the workflow without opening any schema.

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?

Explicit selection condition: use this 'when you do not have a public video_url,' which also implicitly excludes the direct-URL path. It names the downstream alternative (create-submission-tool) and states exactly what to pass to it, leaving nothing to inference.

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