browser_upload_file · AWS IoT SiteWise MCP Server MCP

WHAT IT DOES

What browser_upload_file does on AWS IoT SiteWise MCP Server

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

WHY IT NEEDS A POLICY

Why browser_upload_file needs a policy

File upload operations create or modify data in a system, fitting the Write category. Severity is medium because uploads can introduce malicious files or overwrite legitimate content, but lack of description limits confidence. If this tool permits arbitrary file uploads to sensitive AWS IoT SiteWise resources without validation, severity could escalate to high.

From the tool's definition Tool name 'browser_upload_file' indicates file upload functionality; description is empty but context from sibling tools (add_attachments_to_set, add_inline_policy) suggests data creation/modification operations typical of AWS service management.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_upload_file Rate-limited

browser_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": {
    "browser_upload_file": {
      "limits": [
        {
          "counter": "browser_upload_file_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 AWS IoT SiteWise MCP Server, so you can run agents against it safely.

FAQ

Questions about browser_upload_file

What does the browser_upload_file tool do? +

browser_upload_file. It is categorised as a Write tool in the AWS IoT SiteWise 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 browser_upload_file? +

Register the AWS IoT SiteWise MCP Server MCP server in PolicyLayer and add a rule for browser_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 AWS IoT SiteWise MCP Server. Nothing to install.

What risk level is browser_upload_file? +

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

Can I rate-limit browser_upload_file? +

Yes. Add a rate_limit block to the browser_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 browser_upload_file completely? +

Set action: deny in the PolicyLayer policy for browser_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 browser_upload_file? +

browser_upload_file is provided by the AWS IoT SiteWise MCP Server MCP server (awslabs.aws-iot-sitewise-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.