register_database · NDB MCP Server MCP: Risk & Policy

WHAT IT DOES

What register_database does on NDB MCP Server

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

WHY IT NEEDS A POLICY

Why register_database needs a policy

This is a Write operation because it creates/registers data in the NDB system, modifying the inventory of managed databases. It is not Read (no query/retrieval), not Execute (doesn't run arbitrary code on the database), not Destructive (registration is reversible via deregister_database, and doesn't delete data), not Financial.

From the tool's definition The tool performs 'Register an existing database with NDB', which creates a new management relationship between an external database and the NDB system. This is a metadata creation/modification operation that establishes configuration state in NDB.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

register_database Rate-limited

register_database 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": {
    "register_database": {
      "limits": [
        {
          "counter": "register_database_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 NDB MCP Server, so you can run agents against it safely.

FAQ

Questions about register_database

What does the register_database tool do? +

Register an existing database with NDB. It is categorised as a Write tool in the NDB 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 register_database? +

Register the NDB MCP Server MCP server in PolicyLayer and add a rule for register_database: 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 NDB MCP Server. Nothing to install.

What risk level is register_database? +

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

Can I rate-limit register_database? +

Yes. Add a rate_limit block to the register_database 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 register_database completely? +

Set action: deny in the PolicyLayer policy for register_database. 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 register_database? +

register_database is provided by the NDB MCP Server MCP server (rouxton/ndb-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.