post_tweet · X MCP: Risk & Policy

WHAT IT DOES

What post_tweet does on X

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

WHY IT NEEDS A POLICY

Why post_tweet needs a policy

An AI agent can call post_tweet faster than any human can review — one bad instruction and it creates or modifies resources in X by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

post_tweet Rate-limited

post_tweet 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": {
    "post_tweet": {
      "limits": [
        {
          "counter": "post_tweet_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 X, so you can run agents against it safely.

FAQ

Questions about post_tweet

What does the post_tweet tool do? +

Post a new tweet to X with optional media attachments. It is categorised as a Write tool in the X MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on post_tweet? +

Register the X MCP server in PolicyLayer and add a rule for post_tweet: 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 X. Nothing to install.

What risk level is post_tweet? +

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

Can I rate-limit post_tweet? +

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

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

post_tweet is provided by the X MCP server (@mbelinky/x-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.