http_put · Http Client MCP: Risk & Policy

WHAT IT DOES

What http_put does on Http Client

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

WHY IT NEEDS A POLICY

Why http_put needs a policy

HTTP PUT typically replaces or creates a resource at a target URL, making it a Write operation. However, since the description is empty, the actual behavior is unknown — it could be used to overwrite critical resources. Severity is high because PUT can fully replace existing data.

From the tool's definition Tool name 'http_put' implies HTTP PUT method, which is a standard write/replace operation. Description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

http_put Rate-limited

http_put 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": {
    "http_put": {
      "limits": [
        {
          "counter": "http_put_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 Http Client, so you can run agents against it safely.

FAQ

Questions about http_put

What does the http_put tool do? +

http_put. It is categorised as a Write tool in the Http Client MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on http_put? +

Register the Http Client MCP server in PolicyLayer and add a rule for http_put: 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 Http Client. Nothing to install.

What risk level is http_put? +

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

Can I rate-limit http_put? +

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

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

http_put is provided by the Http Client MCP server (keijeizei/http-client-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.