AI agents call ListECRRepositories to retrieve information from Prometheus MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
ECR (Elastic Container Registry) list operations retrieve metadata about existing repositories without creating, modifying, or deleting any resources. This is a passive information retrieval action with minimal blast radius. The empty description reduces confidence slightly, but the naming convention strongly indicates a read operation.
From the tool's definition Tool name 'ListECRRepositories' indicates a listing/retrieval operation on AWS ECR repositories. The 'List' verb is characteristic of read-only operations that query and return data without modification.
Documented attack patterns abuse exactly the kind of access ListECRRepositories gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Prometheus MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for ListECRRepositories:
{
"version": "1",
"default": "deny",
"tools": {
"ListECRRepositories": {}
}
}ListECRRepositories is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
ListECRRepositories. It is categorised as a Read tool in the Prometheus MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Prometheus MCP Server MCP server in PolicyLayer and add a rule for ListECRRepositories: 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 Prometheus MCP Server. Nothing to install.
ListECRRepositories is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the ListECRRepositories 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.
Set action: deny in the PolicyLayer policy for ListECRRepositories. 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.
ListECRRepositories is provided by the Prometheus MCP Server MCP server (awslabs.prometheus-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Prometheus MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
805 Prometheus MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.