AI agents use CreateAHORunCache to create or update resources in Prometheus MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Prometheus MCP Server environment.
The 'Create' prefix indicates this tool creates or initializes a new resource (a cache). This is a Write-category action—reversible through deletion or reconfiguration. Severity is medium because unintended cache creation could affect system performance, storage costs, or data organization in AWS Prometheus, but is not destructive or financial in nature.
From the tool's definition Tool name 'CreateAHORunCache' indicates creation/initialization of a cache object. The description is empty, limiting direct evidence, but the 'Create' verb and context within an AWS Prometheus MCP server (which manages time-series data and caching) suggests…
Documented attack patterns abuse exactly the kind of access CreateAHORunCache 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 CreateAHORunCache:
{
"version": "1",
"default": "deny",
"tools": {
"CreateAHORunCache": {
"limits": [
{
"counter": "createahoruncache_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}CreateAHORunCache 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.
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CreateAHORunCache. It is categorised as a Write tool in the Prometheus MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Prometheus MCP Server MCP server in PolicyLayer and add a rule for CreateAHORunCache: 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.
CreateAHORunCache is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the CreateAHORunCache 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 CreateAHORunCache. 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.
CreateAHORunCache 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.
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805 Prometheus MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.