juno_changes_reject · Junobuild MCP: Risk & Policy

WHAT IT DOES

What juno_changes_reject does on Junobuild

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

WHY IT NEEDS A POLICY

Why juno_changes_reject needs a policy

This tool modifies pending changes by rejecting them, which is a Write operation (reversible state modification). It does not delete data permanently (not Destructive), does not execute arbitrary code (not Execute), and does not move money (not Financial).

From the tool's definition Tool description states 'Reject a submitted change by its ID. This prevents the change from being applied.' The action of rejecting a change modifies the state of a pending change, preventing its application—a reversible operation that alters data state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

juno_changes_reject Rate-limited

juno_changes_reject 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": {
    "juno_changes_reject": {
      "limits": [
        {
          "counter": "juno_changes_reject_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 Junobuild, so you can run agents against it safely.

FAQ

Questions about juno_changes_reject

What does the juno_changes_reject tool do? +

Reject a submitted change by its ID. This prevents the change from being applied. Optionally verify the change hash for integrity. It is categorised as a Write tool in the Junobuild MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on juno_changes_reject? +

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

What risk level is juno_changes_reject? +

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

Can I rate-limit juno_changes_reject? +

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

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

juno_changes_reject is provided by the Junobuild MCP server (junobuild-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.