Remove and return members with highest scores.
AI agents call sorted_set_popmax to permanently remove resources in Prometheus MCP Server — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
The tool explicitly removes members from a sorted set, which is a destructive operation that cannot be undone. Even though it also returns the removed data, the primary action is deletion of data from the data store. This warrants a Destructive classification with high severity, as an AI agent misusing this tool could permanently remove important data from the Prometheus-managed data store.
From the tool's definition 'Remove and return members with highest scores' — the remove operation is irreversible
Documented attack patterns abuse exactly the kind of access sorted_set_popmax 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 sorted_set_popmax:
{
"version": "1",
"default": "deny",
"hide": [
"sorted_set_popmax"
]
}sorted_set_popmax disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.
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Remove and return members with highest scores. It is categorised as a Destructive tool in the Prometheus MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Prometheus MCP Server MCP server in PolicyLayer and add a rule for sorted_set_popmax: 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.
sorted_set_popmax is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the sorted_set_popmax 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 sorted_set_popmax. 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.
sorted_set_popmax 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.