db_grant_role_membership · Database MCP Server MCP

WHAT IT DOES

What db_grant_role_membership does on Database MCP Server

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

WHY IT NEEDS A POLICY

Why db_grant_role_membership needs a policy

The tool creates or modifies role membership relationships in the database, which are permission/access control assignments. This is a Write action because it modifies data (role memberships) reversibly—memberships can be revoked. It is not Destructive because role membership modifications are not irreversible deletions.

From the tool's definition Tool name 'db_grant_role_membership' and description 'Grant a role to another role (membership)' indicate modification of role hierarchies and permission assignments. This is a reversible write operation that modifies database access control.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

db_grant_role_membership Rate-limited

db_grant_role_membership 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": {
    "db_grant_role_membership": {
      "limits": [
        {
          "counter": "db_grant_role_membership_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 Database MCP Server, so you can run agents against it safely.

FAQ

Questions about db_grant_role_membership

What does the db_grant_role_membership tool do? +

Grant a role to another role (membership). It is categorised as a Write tool in the Database 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 db_grant_role_membership? +

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

What risk level is db_grant_role_membership? +

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

Can I rate-limit db_grant_role_membership? +

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

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

db_grant_role_membership is provided by the Database MCP Server MCP server (roilanrodriguez55/database-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.