Retrieve a reference media item and its current signed download URL by mediaID to verify uploads, with sourceVideoMediaID for original motion source.
Retrieve an accessible reference media item and its current signed download URL. Use sourceVideoMediaID from a motion to retrieve its original reference. Media registration alone does not prove that file bytes have been uploaded.
| Name | Required | Description | Default |
|---|---|---|---|
| mediaID | Yes |
Changes observed during successful MCP inspections.
v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false. The description adds valuable context beyond that: the URL is a 'current signed download URL' and 'media registration alone does not prove that file bytes have been uploaded,' which prevents the agent from assuming upload completion. No contradiction 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 two sentences with no filler. The main purpose and output are front-loaded in the first sentence, and the important caveat about upload status is placed second. Every sentence contributes necessary 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?
For a simple one-parameter read-only tool, the description is complete: it states the returned data (media item and current signed download URL), explains how to obtain the ID, and warns about the upload caveat. Since there is no output schema, the description adequately covers return semantics.
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?
The schema only provides mediaID as a required string with minLength 1 and no description. The tool description adds meaningful semantic guidance by indicating that mediaID should come from a motion's sourceVideoMediaID. It does not elaborate further on ID format, but for a single required parameter this is a useful addition.
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 opens with a specific verb and resource: 'Retrieve an accessible reference media item and its current signed download URL.' It clearly specifies both the action and the returned data, and distinguishes itself from motion/scene/character siblings by pointing to sourceVideoMediaID from a motion and the original reference relationship.
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 gives clear when-to-use context: use a sourceVideoMediaID from a motion to retrieve the original reference. It does not explicitly name alternative tools or state when not to use this tool, but the guidance is sufficient for a tool with no close sibling overlap.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.