tf_workspace_select · Terraform MCP Server MCP

WHAT IT DOES

What tf_workspace_select does on Terraform MCP Server

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

WHY IT NEEDS A POLICY

Why tf_workspace_select needs a policy

Selecting a workspace changes the active state context for all subsequent Terraform operations. It is a reversible configuration change (you can switch back), so it falls under Write rather than Execute or Destructive. However, misuse could cause subsequent plan/apply/destroy operations to target the wrong environment, giving it medium severity.

From the tool's definition "Select workspace" — switches the active Terraform workspace

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

tf_workspace_select Rate-limited

tf_workspace_select 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": {
    "tf_workspace_select": {
      "limits": [
        {
          "counter": "tf_workspace_select_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Terraform MCP Server, so you can run agents against it safely.

FAQ

Questions about tf_workspace_select

What does the tf_workspace_select tool do? +

Select workspace. It is categorised as a Write tool in the Terraform 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 tf_workspace_select? +

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

What risk level is tf_workspace_select? +

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

Can I rate-limit tf_workspace_select? +

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

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

tf_workspace_select is provided by the Terraform MCP Server MCP server (mjrestivo16/mcp-terraform). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.