update_agent_runtime · Awslabs Valkey MCP: Risk & Policy

WHAT IT DOES

What update_agent_runtime does on Awslabs Valkey

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

WHY IT NEEDS A POLICY

Why update_agent_runtime needs a policy

The 'update_' verb clearly indicates a reversible modification operation rather than deletion (Destructive) or code execution (Execute). In the context of an AWS ElastiCache/MemoryDB server managing agents, updating runtime parameters could affect system behavior and performance, warranting 'high' severity.

From the tool's definition Tool name 'update_agent_runtime' indicates modification of runtime configuration or state for an agent. The 'update_' prefix establishes this as a write operation. Empty description prevents full confidence assessment.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_agent_runtime Rate-limited

update_agent_runtime 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": {
    "update_agent_runtime": {
      "limits": [
        {
          "counter": "update_agent_runtime_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 Awslabs Valkey, so you can run agents against it safely.

FAQ

Questions about update_agent_runtime

What does the update_agent_runtime tool do? +

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

How do I enforce a policy on update_agent_runtime? +

Register the Awslabs Valkey MCP server in PolicyLayer and add a rule for update_agent_runtime: 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 Awslabs Valkey. Nothing to install.

What risk level is update_agent_runtime? +

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

Can I rate-limit update_agent_runtime? +

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

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

update_agent_runtime is provided by the Awslabs Valkey MCP server (awslabs.valkey-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.