register_skill · Tenzro Ledger MCP: Risk & Policy

WHAT IT DOES

What register_skill does on Tenzro Ledger MCP

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

WHY IT NEEDS A POLICY

Why register_skill needs a policy

This tool creates/adds a new entry (skill) to a registry, which is a reversible data modification. It does not execute arbitrary code, move money, delete data, or trigger external operations with unpredictable effects. The blast radius is moderate because registering a malicious or unintended skill could affect downstream systems that consume the registry, but the operation is not inherently destructive or financial.

From the tool's definition Tool description states 'Register a new skill in the skills registry' — a create operation that adds new data to a registry without deletion or irreversible side effects.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

register_skill Rate-limited

register_skill 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_skill": {
      "limits": [
        {
          "counter": "register_skill_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 Tenzro Ledger MCP, so you can run agents against it safely.

FAQ

Questions about register_skill

What does the register_skill tool do? +

Register a new skill in the skills registry. It is categorised as a Write tool in the Tenzro Ledger MCP 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_skill? +

Register the Tenzro Ledger MCP server in PolicyLayer and add a rule for register_skill: 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 Tenzro Ledger MCP. Nothing to install.

What risk level is register_skill? +

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

Can I rate-limit register_skill? +

Yes. Add a rate_limit block to the register_skill 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_skill completely? +

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

register_skill is provided by the Tenzro Ledger MCP server (https://canton-mcp.tenzro.network/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.