update_access_control_policy

WHAT IT DOES

What update_access_control_policy does on ReliaQuest GreyMatter MCP Server

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

WHY IT NEEDS A POLICY

Why update_access_control_policy needs a policy

This tool updates access control policies, which is a reversible write operation affecting security configurations. While modifications to access control can have significant blast radius (potentially granting or revoking system access), the operation is not inherently destructive, financial, or code execution.

From the tool's definition Tool is named 'update_access_control_policy' and described as a 'mutation updateAccessControlPolicy' that accepts an 'input' parameter for modifying access control policies.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_access_control_policy Rate-limited

update_access_control_policy 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": {
    "update_access_control_policy": {
      "limits": [
        {
          "counter": "update_access_control_policy_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 ReliaQuest GreyMatter MCP Server, so you can run agents against it safely.

FAQ

Questions about update_access_control_policy

What does the update_access_control_policy tool do? +

DRP Access Control \u00b7 mutation updateAccessControlPolicy. Variables: after, first, notFilter, order, after1, first1, notFilter1, input. Example variables: {\. It is categorised as a Write tool in the ReliaQuest GreyMatter 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 update_access_control_policy? +

Register the ReliaQuest GreyMatter MCP Server MCP server in PolicyLayer and add a rule for update_access_control_policy: 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 ReliaQuest GreyMatter MCP Server. Nothing to install.

What risk level is update_access_control_policy? +

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

Can I rate-limit update_access_control_policy? +

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

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

update_access_control_policy is provided by the ReliaQuest GreyMatter MCP Server MCP server (space-c0wboy/reliaquest-greymatter-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.