release_build_slot · MCP Agent Mail MCP: Risk & Policy

WHAT IT DOES

What release_build_slot does on MCP Agent Mail

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

WHY IT NEEDS A POLICY

Why release_build_slot needs a policy

Based on the tool name 'release_build_slot' and the server context involving build slot acquisition (sibling tool: acquire_build_slot) and file reservation leases in a multi-agent environment, this tool likely releases a previously acquired build slot, freeing it for other agents. This is a Write/state-modification action (reversible resource management).

From the tool's definition Tool name: release_build_slot; description is empty.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

release_build_slot Rate-limited

release_build_slot 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": {
    "release_build_slot": {
      "limits": [
        {
          "counter": "release_build_slot_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 MCP Agent Mail, so you can run agents against it safely.

FAQ

Questions about release_build_slot

What does the release_build_slot tool do? +

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

How do I enforce a policy on release_build_slot? +

Register the MCP Agent Mail MCP server in PolicyLayer and add a rule for release_build_slot: 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 MCP Agent Mail. Nothing to install.

What risk level is release_build_slot? +

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

Can I rate-limit release_build_slot? +

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

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

release_build_slot is provided by the MCP Agent Mail MCP server (omelchmichael/mcp_agent_mail). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.