Download a completed HeyGen job to the local outputs directory without overwriting existing files; returns the saved file path and SHA256 hash. Does not create new generations.
Download an existing completed job into HEYGEN_DATA_DIR/outputs; never overwrite. Returns local path and SHA256. No new generation.
| Name | Required | Description | Default |
|---|---|---|---|
| job_id | Yes | ||
| filename | No | video.mp4 |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Adds real context beyond the annotations: it writes into a specific directory, refuses to overwrite, and reports a local path plus SHA256 for integrity checking. That 'never overwrite' guarantee is exactly the behavior an agent needs, though it doesn't say whether a collision raises an error or picks a new name.
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?
Three short clauses, each earning its place: action plus destination, the overwrite guarantee, and the return value. Front-loaded with 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?
Output schema exists so return values needn't be spelled out, but two gaps remain for a tool that writes to disk: behavior when the target file already exists, and behavior when the job isn't complete yet. The filename parameter's role is left entirely implicit.
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%, so the description must carry both parameters, and it explains neither. job_id is only indirectly constrained by 'completed job', and the filename parameter (default video.mp4) — the one that interacts with the 'never overwrite' rule — is never mentioned.
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 existing completed job') plus the destination ('HEYGEN_DATA_DIR/outputs'), and the closing 'No new generation' rules out the generation siblings like heygen_submit. It never names heygen_status or heygen_receipt, so differentiation is by negation rather than explicit routing.
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?
'existing completed job' implies a precondition (the job must already be finished) but never tells the agent to verify via heygen_status first, nor what to do if the job is still running. No alternatives are named; usage is inferable rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.