iac_mcp_set_value · Iac MCP: Risk & Policy

WHAT IT DOES

What iac_mcp_set_value does on Iac

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

WHY IT NEEDS A POLICY

Why iac_mcp_set_value needs a policy

This tool modifies UI element values (text fields, text areas, checkboxes) which can change application state and user-facing data. It is reversible (values can be changed again), so it qualifies as Write rather than Destructive.

From the tool's definition Tool description explicitly states it 'Set the value of a UI element' and works with 'text fields, text areas, checkboxes, and other value-holding elements.' The verb 'Set' combined with ability to modify multiple UI element types indicates data modification…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

iac_mcp_set_value Rate-limited

iac_mcp_set_value 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": {
    "iac_mcp_set_value": {
      "limits": [
        {
          "counter": "iac_mcp_set_value_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 Iac, so you can run agents against it safely.

FAQ

Questions about iac_mcp_set_value

What does the iac_mcp_set_value tool do? +

Set the value of a UI element identified by a reference from ui_snapshot. Works with text fields, text areas, checkboxes, and other value-holding elements. Usage: 1. First call ui_snapshot to get element references 2. Find the text field or checkbox you want to modify 3. Pass its reference ID and the new value Examples: - Set text field: ref:. It is categorised as a Write tool in the Iac MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on iac_mcp_set_value? +

Register the Iac MCP server in PolicyLayer and add a rule for iac_mcp_set_value: 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 Iac. Nothing to install.

What risk level is iac_mcp_set_value? +

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

Can I rate-limit iac_mcp_set_value? +

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

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

iac_mcp_set_value is provided by the Iac MCP server (jsavin/iac-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.