fix_subtitles

THE RISK

High Risk

Why fix_subtitles needs a policy

This tool modifies files by converting subtitle formats inside MKV files. It writes/overwrites subtitle tracks in media files, and operates on potentially an entire folder. While it is a transformation operation, it overwrites existing subtitle data in files, making it at least a Write operation.

From the tool's definition Convert ASS/SSA subtitles to SRT in MKV files to prevent transcoding. Works on single file or entire folder.

Risk signalsBulk/mass operation — affects multiple targets

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

POLICY

How to control fix_subtitles

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

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "fix_subtitles": {
      "limits": [
        {
          "counter": "fix_subtitles_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

fix_subtitles stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

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

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Mediabox MCP tools

Destructive cancel_downloads Manage Sonarr/Radarr/qBittorrent download queues. NOT for PyLoad — use download_status act Destructive cleanup_server Clean up the server: remove Jellyfin cache, temp files, orphan downloads, ghost entries in Destructive movie_remove Remove a movie from Radarr Destructive series_remove Remove a series from Sonarr Destructive manage_files List, move, or delete files and folders. Paths starting with Execute download_direct Download a file from a direct URL (or YouTube/video site via yt-dlp) and optionally organi Execute download_status PyLoad download manager. Three actions: - status: shows PyLoad queue AND lists folders in Execute movie_grab Download a specific torrent release for a movie. Automatically cancels any existing downlo

All 30 Mediabox MCP tools →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

High-risk tools in Mediabox MCP → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about fix_subtitles

What does the fix_subtitles tool do? +

Convert ASS/SSA subtitles to SRT in MKV files to prevent transcoding. Works on single file or entire folder. It is categorised as a Execute tool in the Mediabox MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on fix_subtitles? +

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

What risk level is fix_subtitles? +

fix_subtitles is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit fix_subtitles? +

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

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

fix_subtitles is provided by the Mediabox MCP server (juancmpdev/mediabox-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Mediabox MCP tool call.

Start from Mediabox MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →