send_otp · Nubra MCP Server MCP: Risk & Policy

WHAT IT DOES

What send_otp does on Nubra MCP Server

AI agents use send_otp to create or update resources in Nubra MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Nubra MCP Server environment.

WHY IT NEEDS A POLICY

Why send_otp needs a policy

The tool generates and sends an OTP (One-Time Password), which modifies the authentication state of the user's session. While authentication operations can affect security posture, this specific action is reversible—OTPs expire and new ones can be generated. It does not execute arbitrary code, delete data, move money, or trigger irreversible changes.

From the tool's definition Tool description states 'Send an OTP for the selected environment', which creates/modifies authentication state by generating and delivering a one-time password. This is a write operation that initiates a reversible authentication flow.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_otp Rate-limited

send_otp stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "send_otp": {
      "limits": [
        {
          "counter": "send_otp_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Nubra MCP Server, so you can run agents against it safely.

FAQ

Questions about send_otp

What does the send_otp tool do? +

Send an OTP for the selected environment. After this, ask for the OTP and call verify_otp or verify_otp_with_saved_mpin. It is categorised as a Write tool in the Nubra MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on send_otp? +

Register the Nubra MCP Server MCP server in PolicyLayer and add a rule for send_otp: 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.

What risk level is send_otp? +

send_otp is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit send_otp? +

Yes. Add a rate_limit block to the send_otp 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.

How do I block send_otp completely? +

Set action: deny in the PolicyLayer policy for send_otp. 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.

What MCP server provides send_otp? +

send_otp 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.