get_alert

THE RISK

Low Risk

Why get_alert needs a policy

This tool retrieves/queries alert information by ID from the Mackerel monitoring platform with no side effects. It does not create, modify, delete, execute external operations, or commit financial obligations. The context shows it is part of a monitoring platform's read operations alongside similar tools like get_dashboard, get_host_metrics, and get_trace.

From the tool's definition Tool name 'get_alert' and description 'Retrieve a specific alert by ID from Mackerel' indicate retrieval of existing data without modification.

Documented attack patterns abuse exactly the kind of access get_alert gives an agent:

POLICY

How to control get_alert

PolicyLayer is an MCP gateway — it sits between your AI agents and Mackerel MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for get_alert:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "get_alert": {}
  }
}

get_alert is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register Mackerel MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Mackerel MCP Server tools

Write update_dashboard Update a specific dashboard by ID in Mackerel. 🔍 USE THIS TOOL WHEN USERS: - Modify dash Read get_alert_logs Retrieve logs for a specific alert by ID from Mackerel. 🔍 USE THIS TOOL WHEN USERS: - Vi Read get_dashboard Retrieve a specific dashboard by ID from Mackerel. 🔍 USE THIS TOOL WHEN USERS: - Get det Read get_host_metrics Retrieve metrics data for a specific host from Mackerel. 🔍 USE THIS TOOL WHEN USERS: - G Read get_monitor Retrieve a specific monitor configuration by ID from Mackerel. 🔍 USE THIS TOOL WHEN USER Read get_service_metrics Retrieve metrics data for a specific service from Mackerel. 🔍 USE THIS TOOL WHEN USERS: Read get_trace Retrieve trace data by trace ID from Mackerel for distributed tracing analysis. 🔍 USE TH Read list_alerts Retrieve alerts from Mackerel. 🔍 USE THIS TOOL WHEN USERS: - Check currently active aler

All 16 Mackerel MCP Server tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about get_alert

What does the get_alert tool do? +

Retrieve a specific alert by ID from Mackerel. 🔍 USE THIS TOOL WHEN USERS: - Investigate a particular alert <examples> Get alert by ID \. It is categorised as a Read tool in the Mackerel MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on get_alert? +

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

What risk level is get_alert? +

get_alert is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit get_alert? +

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

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

get_alert is provided by the Mackerel MCP Server MCP server (mackerelio-labs/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Mackerel MCP Server tool call.

Start from Mackerel MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →