register-skills · Mmc MCP: Risk & Policy

WHAT IT DOES

What register-skills does on Mmc

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

WHY IT NEEDS A POLICY

Why register-skills needs a policy

This tool creates or modifies session-scoped skill definitions. It is Write rather than Execute because it does not directly run code or trigger external operations; it stores/registers configuration. It is not Destructive because registration is reversible (a new session or re-registration can override it).

From the tool's definition Tool description states "Register skill/slice definitions for this session" — this is a create/write operation that establishes new skill definitions. The name "register-skills" also indicates a registration (creation) action rather than retrieval or deletion.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

register-skills 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": {
    "register-skills": {
      "limits": [
        {
          "counter": "register-skills_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 Mmc, so you can run agents against it safely.

FAQ

Questions about register-skills

What does the register-skills tool do? +

Register skill/slice definitions for this session. Skills are session-scoped and isolated from other users. Typically called by the workbench test panel to push the current model. It is categorised as a Write tool in the Mmc MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on register-skills? +

Register the Mmc MCP server in PolicyLayer and add a rule for register-skills: 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 Mmc. Nothing to install.

What risk level is register-skills? +

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

Can I rate-limit register-skills? +

Yes. Add a rate_limit block to the register-skills 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 register-skills completely? +

Set action: deny in the PolicyLayer policy for register-skills. 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 register-skills? +

register-skills is provided by the Mmc MCP server (modelmycontext/mmc-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.