hue_upload_file · Hue MCP Server MCP: Risk & Policy

WHAT IT DOES

What hue_upload_file does on Hue MCP Server

AI agents use hue_upload_file to create or update resources in Hue MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Hue MCP Server environment.

WHY IT NEEDS A POLICY

Why hue_upload_file needs a policy

The tool performs data creation/modification in HDFS, fitting the Write category. Severity is high because: (1) uploading files to a shared Hadoop cluster could overwrite existing data affecting multiple users; (2) large file uploads could consume significant cluster resources; (3) malicious file uploads could introduce security risks or corrupt data pipelines.

From the tool's definition The tool is described as 'Upload a local file to HDFS,' which creates new data in the distributed file system. This is a write operation that modifies the file system state by adding or overwriting files.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

hue_upload_file Rate-limited

hue_upload_file 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "hue_upload_file": {
      "limits": [
        {
          "counter": "hue_upload_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

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

FAQ

Questions about hue_upload_file

What does the hue_upload_file tool do? +

Upload a local file to HDFS. It is categorised as a Write tool in the Hue MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on hue_upload_file? +

Register the Hue MCP Server MCP server in PolicyLayer and add a rule for hue_upload_file: 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 Hue MCP Server. Nothing to install.

What risk level is hue_upload_file? +

hue_upload_file is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit hue_upload_file? +

Yes. Add a rate_limit block to the hue_upload_file 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 hue_upload_file completely? +

Set action: deny in the PolicyLayer policy for hue_upload_file. 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 hue_upload_file? +

hue_upload_file is provided by the Hue MCP Server MCP server (spanishst/hueclientrest-mpc). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.