xert-upload-fit · XERT Cycling Training MCP: Risk & Policy

WHAT IT DOES

What xert-upload-fit does on XERT Cycling Training

AI agents use xert-upload-fit to create or update resources in XERT Cycling Training — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your XERT Cycling Training environment.

WHY IT NEEDS A POLICY

Why xert-upload-fit needs a policy

This tool creates and adds data (a workout activity) to the XERT account, making it a Write operation. It is reversible (the activity can be deleted later), so not Destructive. Severity is medium because uploading malicious or incorrect data could corrupt training records and mislead fitness analysis, but the blast radius is limited to the user's own account and cycling analytics (not financial, not system-wide).

From the tool's definition Tool description states 'Upload a FIT file to XERT' and 'activity will be processed and added to your XERT account' — this creates a new record (activity) in the user's account.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

xert-upload-fit Rate-limited

xert-upload-fit 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": {
    "xert-upload-fit": {
      "limits": [
        {
          "counter": "xert-upload-fit_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about xert-upload-fit

What does the xert-upload-fit tool do? +

Upload a FIT file to XERT for analysis. The activity will be processed and added to your XERT account. It is categorised as a Write tool in the XERT Cycling Training MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on xert-upload-fit? +

Register the XERT Cycling Training MCP server in PolicyLayer and add a rule for xert-upload-fit: 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 XERT Cycling Training. Nothing to install.

What risk level is xert-upload-fit? +

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

Can I rate-limit xert-upload-fit? +

Yes. Add a rate_limit block to the xert-upload-fit 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 xert-upload-fit completely? +

Set action: deny in the PolicyLayer policy for xert-upload-fit. 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 xert-upload-fit? +

xert-upload-fit is provided by the XERT Cycling Training MCP server (milofax/xert-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.