Start a new Pipecat Voice Agent. Once the voice agent has started you can continuously use the listen() and speak() tools to talk to the user. Returns true if the agent was started successfully, false otherwise.
AI agents invoke start to trigger actions in Pipecat MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This tool triggers the initiation of a voice agent system, which is an external operation whose effects (voice interactions, potential actions taken by the agent) depend on subsequent user inputs and agent behavior. This fits the Execute category as it runs/triggers an external operation (speech-to-text and text-to-speech services via Pipecat).
From the tool's definition The tool description states it will 'Start a new Pipecat Voice Agent' and enable continuous voice interactions via listen() and speak().
Documented attack patterns abuse exactly the kind of access start gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Pipecat MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for start:
{
"version": "1",
"default": "deny",
"tools": {
"start": {
"limits": [
{
"counter": "start_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}start stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Start a new Pipecat Voice Agent. Once the voice agent has started you can continuously use the listen() and speak() tools to talk to the user. Returns true if the agent was started successfully, false otherwise. It is categorised as a Execute tool in the Pipecat MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Pipecat MCP Server MCP server in PolicyLayer and add a rule for start: 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 Pipecat MCP Server. Nothing to install.
start is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the start 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 start. 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.
start is provided by the Pipecat MCP Server MCP server (pipecat-ai/pipecat-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 7 Pipecat MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
7 Pipecat MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.