Get the schema representation from Cube.js (GET /schema).
AI agents call get_schema to retrieve information from Cube Js MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves metadata about available cubes, measures, and dimensions without modifying data or executing analytics queries. It is a read-only operation that returns schema information needed for understanding the data structure. The GET request method and passive retrieval nature confirm this is a Read category tool with low severity, as schema information alone poses minimal risk even if misused.
From the tool's definition Tool performs a GET request to retrieve schema representation from Cube.js. The description explicitly states 'Get the schema representation' with no mention of modification, deletion, or execution of queries.
Documented attack patterns abuse exactly the kind of access get_schema gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Cube Js MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for get_schema:
{
"version": "1",
"default": "deny",
"tools": {
"get_schema": {}
}
}get_schema 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.
Get the schema representation from Cube.js (GET /schema). It is categorised as a Read tool in the Cube Js MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Cube Js MCP Server MCP server in PolicyLayer and add a rule for get_schema: 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 Cube Js MCP Server. Nothing to install.
get_schema 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 get_schema 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 get_schema. 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.
get_schema is provided by the Cube Js MCP Server MCP server (zsembek/cube.js-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Cube Js 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.
10 Cube Js MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.