AI agents call search_epub to retrieve information from MCP Document Reader without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Search operations on documents are fundamentally read-only queries that retrieve information without modifying, deleting, or executing code. Even though the description is empty, the tool name and the clear read-only pattern of the entire server strongly indicate this is a data retrieval tool.
From the tool's definition Tool name 'search_epub' and sibling tools like 'read_pdf_page_range', 'read_pdf_pages', 'get_pdf_metadata' all indicate document retrieval operations. The server's stated purpose is 'interact with PDF and EPUB documents'.
Documented attack patterns abuse exactly the kind of access search_epub gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP Document Reader, and nothing reaches the server without passing your rules. This is the rule we recommend for search_epub:
{
"version": "1",
"default": "deny",
"tools": {
"search_epub": {}
}
}search_epub is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
search_epub. It is categorised as a Read tool in the MCP Document Reader MCP Server, which means it retrieves data without modifying state.
Register the MCP Document Reader MCP server in PolicyLayer and add a rule for search_epub: 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 MCP Document Reader. Nothing to install.
search_epub 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 search_epub 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 search_epub. 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.
search_epub is provided by the MCP Document Reader MCP server (jbchouinard/mcp-document-reader). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MCP Document Reader, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
8 MCP Document Reader tools catalogued and risk-classified — across an index of 43,000+ MCP servers.