create_spec · Spec Kit MCP: Risk & Policy

WHAT IT DOES

What create_spec does on Spec Kit

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

WHY IT NEEDS A POLICY

Why create_spec needs a policy

This tool creates new data (specifications) within the management system. It is reversible (the created spec can be deleted or modified) and has no destructive capability. While it modifies the system state, the blast radius is limited to adding a new specification document.

From the tool's definition Tool name 'create_spec' and description 'Create a new specification from a template' indicate data creation/modification. The word 'Create' is a classic Write operation that adds a new entity (a specification document) to the system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_spec Rate-limited

create_spec 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": {
    "create_spec": {
      "limits": [
        {
          "counter": "create_spec_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 Spec Kit, so you can run agents against it safely.

FAQ

Questions about create_spec

What does the create_spec tool do? +

Create a new specification from a template. It is categorised as a Write tool in the Spec Kit MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_spec? +

Register the Spec Kit MCP server in PolicyLayer and add a rule for create_spec: 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 Spec Kit. Nothing to install.

What risk level is create_spec? +

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

Can I rate-limit create_spec? +

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

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

create_spec is provided by the Spec Kit MCP server (@fast-kit/spec-kit). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.