update_agent · CustomGPT MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_agent does on CustomGPT MCP Server

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

WHY IT NEEDS A POLICY

Why update_agent needs a policy

This tool modifies agent configuration/metadata through a non-destructive update operation. While it could impact behavior if malicious changes are made to agent settings, the changes are not permanent and can be undone. It does not execute code, delete data, or move money, placing it in the Write category.

From the tool's definition Tool name 'update_agent' and description 'Update an agent's basic information' indicate modification of existing data. The action is reversible (can be updated again or reverted), and relates to metadata rather than destructive operations or code execution.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_agent Rate-limited

update_agent 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_agent": {
      "limits": [
        {
          "counter": "update_agent_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 CustomGPT MCP Server, so you can run agents against it safely.

FAQ

Questions about update_agent

What does the update_agent tool do? +

Update an agent's basic information. It is categorised as a Write tool in the CustomGPT 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_agent? +

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

What risk level is update_agent? +

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

Can I rate-limit update_agent? +

Yes. Add a rate_limit block to the update_agent 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_agent completely? +

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

update_agent is provided by the CustomGPT MCP Server MCP server (poll-the-people/customgpt-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.