ack_signal · Agent Memory Bridge MCP: Risk & Policy

WHAT IT DOES

What ack_signal does on Agent Memory Bridge

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

WHY IT NEEDS A POLICY

Why ack_signal needs a policy

The name implies a state-modification operation rather than retrieval (Read), execution (Execute), deletion (Destructive), or financial action. Given the context of an agent memory system, 'ack' typically means confirming receipt or processing of data. However, confidence is moderate due to empty description—the tool could potentially be a no-op or have unexpected side effects.

From the tool's definition Tool name 'ack_signal' suggests acknowledgment/confirmation of a signal with no description provided. Likely modifies internal state (e.g., marking a memory signal as acknowledged).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ack_signal Rate-limited

ack_signal 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": {
    "ack_signal": {
      "limits": [
        {
          "counter": "ack_signal_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 Agent Memory Bridge, so you can run agents against it safely.

FAQ

Questions about ack_signal

What does the ack_signal tool do? +

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

How do I enforce a policy on ack_signal? +

Register the Agent Memory Bridge MCP server in PolicyLayer and add a rule for ack_signal: 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 Agent Memory Bridge. Nothing to install.

What risk level is ack_signal? +

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

Can I rate-limit ack_signal? +

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

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

ack_signal is provided by the Agent Memory Bridge MCP server (zzhang82/agent-memory-bridge). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.