cert_renew · Git Steer MCP: Risk & Policy

WHAT IT DOES

What cert_renew does on Git Steer

AI agents invoke cert_renew to trigger actions in Git Steer. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why cert_renew needs a policy

While the tool performs a delete operation (which could suggest Destructive category), the deletion of a certificate Secret is not a permanent data loss—it is a trigger for an automated re-issuance process managed by cert-manager, making this primarily an Execute action that invokes external operations.

From the tool's definition Tool description states it 'Deletes the certificate Secret to force cert-manager to re-issue, or creates a PR to update certificate manifests.' The deletion of secrets and triggering of external certificate management processes constitute irreversible…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cert_renew Rate-limited

cert_renew stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "cert_renew": {
      "limits": [
        {
          "counter": "cert_renew_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about cert_renew

What does the cert_renew tool do? +

Trigger certificate renewal for expiring certificates. Deletes the certificate Secret to force cert-manager to re-issue, or creates a PR to update certificate manifests. It is categorised as a Execute tool in the Git Steer MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on cert_renew? +

Register the Git Steer MCP server in PolicyLayer and add a rule for cert_renew: 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 Git Steer. Nothing to install.

What risk level is cert_renew? +

cert_renew is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit cert_renew? +

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

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

cert_renew is provided by the Git Steer MCP server (ry-ops/git-steer). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.