AI agents call extend_context_from_files to retrieve information from Ai Books without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool reads and queries files to augment context length; it does not create, modify, delete, or execute code. The temporary compression is an implementation detail for efficient retrieval. No side effects occur beyond returning context data to the LLM.
From the tool's definition Tool description states it 'Loads multiple files' and 'retrieves relevant context' — pure data retrieval with no modification or deletion. The compression is temporary and used only to extract relevant information.
Attacks that exploit this kind of access
Loads multiple files, compresses them into temporary libraries, and retrieves relevant context. It is categorised as a Read tool in the Ai Books MCP Server, which means it retrieves data without modifying state.
Register the Ai Books MCP server in PolicyLayer and add a rule for extend_context_from_files: 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 Ai Books. Nothing to install.
extend_context_from_files 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 extend_context_from_files 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 extend_context_from_files. 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.
extend_context_from_files is provided by the Ai Books MCP server (nvmtoxic/ai-books-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.
Teams ship this data inside their own products. See what a licence covers →