run_dax_tests · Power BI MCP Server MCP: Risk & Policy

WHAT IT DOES

What run_dax_tests does on Power BI MCP Server

AI agents invoke run_dax_tests to trigger actions in Power BI MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why run_dax_tests needs a policy

This tool runs arbitrary DAX code provided inline or from external files against a live Power BI model. While the stated purpose is regression testing (defensive), the mechanism allows execution of any DAX expression, which qualifies as Execute rather than Read. The high severity reflects that malicious DAX could exfiltrate sensitive data, corrupt calculations, or consume resources.

From the tool's definition Tool executes DAX queries ("Run a suite of DAX regression tests", "each test is {name, dax, expected}") against Power BI models.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

run_dax_tests Rate-limited

run_dax_tests stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "run_dax_tests": {
      "limits": [
        {
          "counter": "run_dax_tests_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Power BI MCP Server, so you can run agents against it safely.

FAQ

Questions about run_dax_tests

What does the run_dax_tests tool do? +

Run a suite of DAX regression tests against the model: each test is {name, dax, expected, tolerance?}; returns PASS/FAIL per test and an overall verdict. Use to catch measure regressions before deploy. Provide tests inline or via tests_path (JSON file). It is categorised as a Execute tool in the Power BI MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on run_dax_tests? +

Register the Power BI MCP Server MCP server in PolicyLayer and add a rule for run_dax_tests: 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 Power BI MCP Server. Nothing to install.

What risk level is run_dax_tests? +

run_dax_tests is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit run_dax_tests? +

Yes. Add a rate_limit block to the run_dax_tests 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.

How do I block run_dax_tests completely? +

Set action: deny in the PolicyLayer policy for run_dax_tests. 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.

What MCP server provides run_dax_tests? +

run_dax_tests is provided by the Power BI MCP Server MCP server (sulaiman013/powerbi-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.