update_skill · Zanat MCP: Risk & Policy

WHAT IT DOES

What update_skill does on Zanat

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

WHY IT NEEDS A POLICY

Why update_skill needs a policy

The tool creates or modifies data (skills) in a reversible manner—updates can be undone by updating again or restoring from backup. It does not delete data (which would be Destructive) nor execute arbitrary code (which would be Execute).

From the tool's definition Tool description explicitly states 'Update skill(s) from the hub', which indicates modification of data. The description clarifies it modifies skill records and respects pinning constraints.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_skill Rate-limited

update_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": {
    "update_skill": {
      "limits": [
        {
          "counter": "update_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 Zanat, so you can run agents against it safely.

FAQ

Questions about update_skill

What does the update_skill tool do? +

Update skill(s) from the hub. If a skill name is provided, updates that skill. Otherwise, updates all non-pinned skills. Pinned skills are always skipped. It is categorised as a Write tool in the Zanat MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_skill? +

Register the Zanat MCP server in PolicyLayer and add a rule for update_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 Zanat. Nothing to install.

What risk level is update_skill? +

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

Can I rate-limit update_skill? +

Yes. Add a rate_limit block to the update_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 update_skill completely? +

Set action: deny in the PolicyLayer policy for update_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 update_skill? +

update_skill is provided by the Zanat MCP server (@iamramo/zanat-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.