stop_build · Jenkins MCP: Risk & Policy

WHAT IT DOES

What stop_build does on Jenkins

AI agents invoke stop_build to trigger actions in Jenkins. 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 stop_build needs a policy

This tool executes a command that controls CI/CD infrastructure. While not destructive (the build can be restarted) and not financial, it is an Execute category tool because it triggers an external operation with real-world consequences—interrupting active builds affects development pipelines, deployment schedules, and team workflows.

From the tool's definition Tool name 'stop_build' performs an action that triggers external operations (stopping a Jenkins build) whose effects depend on arguments (which build to stop). The server description notes it enables 'controlling Jenkins jobs' through natural language.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

stop_build Rate-limited

stop_build 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": {
    "stop_build": {
      "limits": [
        {
          "counter": "stop_build_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 Jenkins, so you can run agents against it safely.

FAQ

Questions about stop_build

What does the stop_build tool do? +

Stop a specific build. It is categorised as a Execute tool in the Jenkins MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on stop_build? +

Register the Jenkins MCP server in PolicyLayer and add a rule for stop_build: 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 Jenkins. Nothing to install.

What risk level is stop_build? +

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

Can I rate-limit stop_build? +

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

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

stop_build is provided by the Jenkins MCP server (mcpland/jenkins-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.