Final login step. After the user provides MPIN, call this to establish the session, then resume the original task.
AI agents call verify_mpin to retrieve information from Nubra MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Even though verify_mpin only reads data, uncontrolled read access leaks sensitive information and racks up API costs — an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
Final login step. After the user provides MPIN, call this to establish the session, then resume the original task. It is categorised as a Read tool in the Nubra MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Nubra MCP Server MCP server in PolicyLayer and add a rule for verify_mpin: 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 Nubra MCP Server. Nothing to install.
verify_mpin 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 verify_mpin 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 verify_mpin. 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.
verify_mpin is provided by the Nubra MCP Server MCP server (socials-zanskar/nubra-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 →