// MCP TOOL REFERENCE

Medium Risk

meta_cross_post

ServerMeta MCP Server
CategoryWrite

WHAT IT DOES

What meta_cross_post does on Meta MCP Server

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

THE RISK

Medium Risk

Why meta_cross_post needs a policy

This is a Write operation because it creates and publishes new content to social media platforms, which is reversible (posts can be deleted). However, severity is high rather than medium because publishing to live accounts has significant reputational and engagement consequences: a compromised AI agent could rapidly post spam, misinformation, or inappropriate content across two major platforms and their audiences,…

From the tool's definition Tool 'publishes the same content to both a Facebook Page and Instagram simultaneously' and 'creates photo posts on both platforms' and 'creates Reels on both platforms' — the tool modifies user-facing content on live social media accounts by creating posts…

Documented attack patterns abuse exactly the kind of access meta_cross_post gives an agent:

POLICY

How to control meta_cross_post

PolicyLayer is an MCP gateway — it sits between your AI agents and Meta MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for meta_cross_post:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "meta_cross_post": {
      "limits": [
        {
          "counter": "meta_cross_post_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

meta_cross_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.

Create a free account and register Meta MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Meta MCP Server tools

Financial meta_create_adset Creates a new ad set within a campaign. Args: - ad_account_id (string): Ad account ID ( Financial meta_create_campaign Creates a new campaign in a Meta ad account. Args: - ad_account_id (string): Ad account Destructive meta_delete_ad Deletes an ad permanently. Args: - ad_id (string): Ad ID to delete Destructive meta_delete_ad_rule Deletes an automated ad rule. Args: - rule_id (string): Ad rule ID Destructive meta_delete_adset Deletes an ad set permanently. Args: - adset_id (string): Ad set ID to delete Destructive meta_delete_campaign Deletes (archives) a campaign. This cannot be undone. Args: - campaign_id (string): Cam Destructive meta_delete_comment Deletes a comment on a Facebook Page post. Permanent action. Args: - comment_id (string Destructive meta_delete_custom_audience Deletes a custom audience permanently. This cannot be undone. Args: - audience_id (stri

All 200 Meta MCP Server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about meta_cross_post

What does the meta_cross_post tool do? +

Publishes the same content to both a Facebook Page and Instagram simultaneously. Requires: meta_list_pages must be called first to load page tokens. Args: - page_id (string): Facebook Page ID - ig_account_id (string): Instagram professional account ID - message (string): Text content (used as FB post text and IG caption) - image_url (string, optional): Public image URL — creates photo posts on both platforms - video_url (string, optional): Public video URL — creates Reels on both platforms Logic: - If image_url: FB photo post + IG photo post (parallel) - If video_url: FB Reel + IG Reel (parallel) - If text only: FB text post only (IG doesn. It is categorised as a Write tool in the Meta 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 meta_cross_post? +

Register the Meta MCP Server MCP server in PolicyLayer and add a rule for meta_cross_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 Meta MCP Server. Nothing to install.

What risk level is meta_cross_post? +

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

Can I rate-limit meta_cross_post? +

Yes. Add a rate_limit block to the meta_cross_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 meta_cross_post completely? +

Set action: deny in the PolicyLayer policy for meta_cross_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 meta_cross_post? +

meta_cross_post is provided by the Meta MCP Server MCP server (oliverames/meta-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.