aggregation \u00b7 POST /aggregation/group \u2014 Group objects by stuff. Required: metricActionName, metricAnalyticsEventAction, q, from, size, group.
AI agents call aggregation_group to retrieve information from Vicarius vRx MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Despite using POST (which is typically associated with write operations), this tool's purpose is analytical and read-only: it groups and aggregates existing objects without modifying, deleting, or creating data. The presence of query-like parameters (q, from, size, group) and the server's read-only safety enforcement confirms this is a retrieval/analysis operation rather than a destructive or write operation.
From the tool's definition The tool is a POST endpoint for /aggregation/group that groups objects and returns aggregated data. The description indicates it performs a query operation ('q' parameter) to group and analyze existing data with parameters like metricActionName,…
Attacks that exploit this kind of access
aggregation \u00b7 POST /aggregation/group \u2014 Group objects by stuff. Required: metricActionName, metricAnalyticsEventAction, q, from, size, group. It is categorised as a Read tool in the Vicarius vRx MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Vicarius vRx MCP Server MCP server in PolicyLayer and add a rule for aggregation_group: 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 Vicarius vRx MCP Server. Nothing to install.
aggregation_group 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 aggregation_group 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 aggregation_group. 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.
aggregation_group is provided by the Vicarius vRx MCP Server MCP server (space-c0wboy/vicarius-vrx-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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