Updates an existing Vapi assistant
AI agents use update_assistant to create or update resources in Vapi Mcp Server Enhanced — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Vapi Mcp Server Enhanced environment.
An AI agent can call update_assistant faster than any human can review — one bad instruction and it creates or modifies resources in Vapi Mcp Server Enhanced by the hundred, each call as confident as the last.
Attacks that exploit this kind of access
Updates an existing Vapi assistant. It is categorised as a Write tool in the Vapi Mcp Server Enhanced MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Vapi Mcp Server Enhanced MCP server in PolicyLayer and add a rule for update_assistant: 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 Vapi Mcp Server Enhanced. Nothing to install.
update_assistant is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the update_assistant 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 update_assistant. 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.
update_assistant is provided by the Vapi Mcp Server Enhanced MCP server (vapi-mcp-server-enhanced). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.