create_post · Posterly MCP: Risk & Policy

WHAT IT DOES

What create_post does on Posterly

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

WHY IT NEEDS A POLICY

Why create_post needs a policy

This tool creates new social media content that is published to external platforms. While the description confusingly includes 'DESTRUCTIVE WRITE', the actual operation is Write (creates/modifies content reversibly). It should be categorized as Write rather than Destructive, since social media posts can be edited or deleted after publication.

From the tool's definition Tool description states "Schedule or immediately publish a social media post" and explicitly labels it as "DESTRUCTIVE WRITE".

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_post Rate-limited

create_post 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": {
    "create_post": {
      "limits": [
        {
          "counter": "create_post_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 Posterly, so you can run agents against it safely.

FAQ

Questions about create_post

What does the create_post tool do? +

Schedule or immediately publish a social media post. This is a DESTRUCTIVE WRITE that creates content on the user\. It is categorised as a Write tool in the Posterly MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_post? +

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

What risk level is create_post? +

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

Can I rate-limit create_post? +

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

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

create_post is provided by the Posterly MCP server (posterly-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.