List available voices for a TTS engine.
AI agents call list_voices to retrieve information from Voice Bridge without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and lists available voices from a TTS engine—a read-only operation that queries data without modifying, executing code, or causing irreversible changes. It falls clearly into the Read category with low severity since misuse would only return informational data.
From the tool's definition Tool name 'list_voices' and description 'List available voices for a TTS engine' indicate a query/retrieval operation with no side effects.
Attacks that exploit this kind of access
List available voices for a TTS engine. It is categorised as a Read tool in the Voice Bridge MCP Server, which means it retrieves data without modifying state.
Register the Voice Bridge MCP server in PolicyLayer and add a rule for 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 Voice Bridge. Nothing to install.
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 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 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.
list_voices is provided by the Voice Bridge MCP server (Tomorrow-You/voice-bridge). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
list_voices is one line of Voice Bridge's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
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