Request a direct upload URL

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

The description adds significant behavioral context beyond annotations: it explains the purpose of the signed URL (direct upload), the required outbound HTTP PUT capability, and the follow-up actions (reading response or calling confirm_attachment_upload). No contradictions with 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?

The description is concise, with each sentence serving a purpose: purpose, flow, conditions, and alternatives. It is front-loaded with the key action and provides structured guidance without redundancy.

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 the presence of an output schema (not shown but indicated) and the tool's complexity (multi-step flow), the description covers all necessary context: usage conditions, step-by-step flow, prerequisites, and alternatives. It is complete and actionable for an AI agent.

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%, so baseline is 3. The description adds value by explaining that 'mime' is an optional content-type hint and that the server trusts magic bytes for images, and that 'name' should include the extension. This nuance improves parameter understanding.

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 it gets a short-lived signed PUT URL for uploading files, distinguishing it from upload_attachment by avoiding context bloat and handling large files. It specifies the resource (PUT URL) and verb (request/get), making the purpose unambiguous.

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 states when to use this tool (files over 5 MB or to avoid context bloat) and when not to (if host cannot make outbound HTTP PUT, then use upload_attachment). It also provides a clear flow of steps to follow after obtaining the URL.

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