vivid_download_assetDownloads an image or video asset to a local directory and returns the saved file path.
Download an asset (image / video) to a local directory and return the saved path.
| Name | Required | Description | Default |
|---|---|---|---|
| assetId | Yes | ||
| filename | No | Override the file name (extension added from the content type if missing). | |
| outputDir | Yes | Absolute directory path where the file will be written (created if missing). |
Changes observed during successful MCP inspections.
v0.36.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds real value beyond the annotations by disclosing the write-to-disk behaviour and the returned local path. However, it does not explain the destructiveHint=true / idempotentHint=true annotations: whether an existing file is overwritten, how filename collisions are resolved, or what happens if the asset is a non-image/video type. Those are the key behaviours for an agent invoking a destructive filesystem write.
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 zero filler, stating action, scope, destination, and return value. It is efficient, though so terse that it leaves the previously noted behavioural questions unanswered.
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?
It helpfully covers the return value despite there being no output schema, and covers destination semantics via the schema. For a destructive, open-world filesystem-writing tool with three parameters, it omits overwrite behaviour, supported asset types, and failure modes, leaving meaningful gaps.
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?
At 67% schema description coverage, the description needs to compensate and does not — it never mentions assetId, filename, or outputDir, nor explains that assetId is the source asset identifier. The only semantic context (directory created if missing, extension inferred) lives in the schema, not the description.
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 and resource ('Download an asset'), narrows scope to image/video, and adds the side effect plus return value (saved path). It does not explicitly distinguish itself from siblings like vivid_get_asset or vivid_list_assets, so an agent must infer that this is the local-file-retrieval variant.
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?
Usage is only implied: download when you want the binary on disk. There is no explicit guidance on when to choose this over vivid_get_asset (metadata) or vividly_share_asset, and no mention of prerequisites such as authentication or that a local directory is required.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.