AI agents call youtube_download_caption to retrieve information from Youtube without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves caption data without modifying, deleting, or executing any operations. Downloading/reading captions is a read-only action analogous to fetching or querying data. The server context shows destructive and write operations are handled by separate tools (youtube_delete_caption, youtube_delete_video, etc.), confirming this tool's role is purely informational retrieval.
From the tool's definition Tool name 'youtube_download_caption' and description 'Download the raw content of a caption track by its ID' indicate a retrieval operation with no side effects.
Attacks that exploit this kind of access
Download the raw content of a caption track by its ID. If \. It is categorised as a Read tool in the Youtube MCP Server, which means it retrieves data without modifying state.
Register the Youtube MCP server in PolicyLayer and add a rule for youtube_download_caption: 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 Youtube. Nothing to install.
youtube_download_caption is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the youtube_download_caption 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.
Set action: deny in the PolicyLayer policy for youtube_download_caption. 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.
youtube_download_caption is provided by the Youtube MCP server (tuitamogamer-gpt/youtube-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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