download_outputReturn a short-lived signed URL to download a completed image or video generation without streaming bytes into the model context.
Return a short-lived signed download URL for a completed generation (does not stream bytes into the model context).
| Name | Required | Description | Default |
|---|---|---|---|
| generationId | Yes |
Changes observed during successful MCP inspections.
v0.1.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the safe read-only profile, and the description adds real value on top: the URL is short-lived and signed, and critically it does not stream bytes into the model context. Remaining gaps are the expiry duration and whether permissions are required to fetch the generation.
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 with a parenthetical that earns its place by preempting the wrong mental model (that this streams file contents). No filler.
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?
With no output schema, the description correctly explains the return value (a URL, not bytes), which is the key thing an agent needs. It stops short of expiration time and failure behavior for incomplete generations, so it is strong but not exhaustive.
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 description coverage is 0% for the single generationId parameter, so the description carries the burden. It implies the ID belongs to a completed generation but adds no format, validity, or error semantics beyond that, only partially compensating for the coverage gap.
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?
States a specific verb (return) and resource (a short-lived signed download URL) scoped to a completed generation. This clearly distinguishes it from get_generation (metadata) and upload_input (the inverse direction) without needing to open either 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?
'for a completed generation' implies the precondition that the generation must already be finished, which hints that wait_generation may be required first. However, no sibling tool is named and there is no explicit when-not-to-use guidance, so usage is only implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.