unshelve_alarm · Yamcs MCP Server MCP: Risk & Policy

WHAT IT DOES

What unshelve_alarm does on Yamcs MCP Server

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

WHY IT NEEDS A POLICY

Why unshelve_alarm needs a policy

Based on the tool name, 'unshelve_alarm' likely reverses a 'shelve' operation on an alarm — restoring it to an active/visible state. This is a reversible modification of alarm state (Write). The empty description lowers confidence. Severity is medium as improper alarm state changes in a mission control system could have operational impact.

From the tool's definition Tool name: unshelve_alarm; description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

unshelve_alarm Rate-limited

unshelve_alarm 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": {
    "unshelve_alarm": {
      "limits": [
        {
          "counter": "unshelve_alarm_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 Yamcs MCP Server, so you can run agents against it safely.

FAQ

Questions about unshelve_alarm

What does the unshelve_alarm tool do? +

unshelve_alarm. It is categorised as a Write tool in the Yamcs MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on unshelve_alarm? +

Register the Yamcs MCP Server MCP server in PolicyLayer and add a rule for unshelve_alarm: 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 Yamcs MCP Server. Nothing to install.

What risk level is unshelve_alarm? +

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

Can I rate-limit unshelve_alarm? +

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

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

unshelve_alarm is provided by the Yamcs MCP Server MCP server (paulmramirez/yamcs-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.