upload_html · Flash Cast MCP: Risk & Policy

WHAT IT DOES

What upload_html does on Flash Cast

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

WHY IT NEEDS A POLICY

Why upload_html needs a policy

This tool creates or modifies project data by accepting HTML input (either as string or file path) and storing it in the project. It is reversible (content can be updated or removed), making it a Write operation rather than Destructive.

From the tool's definition Tool description states '上传 HTML 内容到项目' (upload HTML content to project), which creates/modifies project data. Returns slide count and text summaries, indicating persistent storage of the uploaded content.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

upload_html Rate-limited

upload_html 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": {
    "upload_html": {
      "limits": [
        {
          "counter": "upload_html_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 Flash Cast, so you can run agents against it safely.

FAQ

Questions about upload_html

What does the upload_html tool do? +

上传 HTML 内容到项目。支持直接传入 HTML 字符串或本地文件路径。返回幻灯片数量、每页文本摘要和结构性警告。. It is categorised as a Write tool in the Flash Cast MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on upload_html? +

Register the Flash Cast MCP server in PolicyLayer and add a rule for upload_html: 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 Flash Cast. Nothing to install.

What risk level is upload_html? +

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

Can I rate-limit upload_html? +

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

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

upload_html is provided by the Flash Cast MCP server (trtian/flash-cast-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.