AI agents call heygen_list_voices to retrieve information from UnClick without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
api_key | string | Yes | HeyGen API key |
Parameters from the server's own tool schema.
This tool queries and returns a static list of available voices from HeyGen's API. It performs a read-only operation that does not create, modify, delete, or execute any external actions. The blast radius of misuse is minimal—an AI agent could at worst retrieve the list multiple times or spam requests, but cannot cause data loss, financial impact, or system compromise.
From the tool's definition Tool name 'heygen_list_voices' and description 'List all available voices' indicate a retrieval operation with no side effects.
Risk signalsHandles credentials or secrets (api_key)
Attacks that exploit this kind of access
List all available voices for HeyGen avatar videos. It is categorised as a Read tool in the UnClick MCP Server, which means it retrieves data without modifying state.
heygen_list_voices accepts 1 parameter: api_key. Required: api_key. The full parameter table on this page comes from the server's own tool schema.
Register the UnClick MCP server in PolicyLayer and add a rule for heygen_list_voices: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches UnClick. Nothing to install.
heygen_list_voices is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the heygen_list_voices rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for heygen_list_voices. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
heygen_list_voices is provided by the UnClick MCP server (@unclick/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →