update_post · Viraly MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_post does on Viraly MCP Server

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

WHY IT NEEDS A POLICY

Why update_post needs a policy

This tool creates or modifies data in a reversible manner (updates scheduled posts before publication). It allows changes to captions, scheduling, attachments, and metadata but explicitly cannot affect already-published posts.

From the tool's definition Tool name 'update_post' and description states it can 'Update an existing scheduled post — change the caption, schedule time, attachments, or category.' This modifies existing data reversibly without deletion.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_post Rate-limited

update_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": {
    "update_post": {
      "limits": [
        {
          "counter": "update_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 Viraly MCP Server, so you can run agents against it safely.

FAQ

Questions about update_post

What does the update_post tool do? +

Update an existing scheduled post — change the caption, schedule time, attachments, or category. Provide only the fields you want to change. Cannot update a post that has already been published. To set or change accessibility alt text on media, pass. It is categorised as a Write tool in the Viraly 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 update_post? +

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

What risk level is update_post? +

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

Can I rate-limit update_post? +

Yes. Add a rate_limit block to the update_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 update_post completely? +

Set action: deny in the PolicyLayer policy for update_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 update_post? +

update_post is provided by the Viraly MCP Server MCP server (viraly-io/viraly-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.