read_file_metadata

Read metadata directly from the ebook file itself (EPUB, MOBI, etc.).

SERVERCalibre SOURCE2b3pro/calibre-mcp

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade B, identity unverified Pull the record →

This record as markdown: /tools/2b3pro-calibre-mcp/read-file-metadata.md

WHAT IT DOES

What read_file_metadata does on Calibre

AI agents call read_file_metadata to retrieve information from Calibre without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why read_file_metadata is rated Low

This tool retrieves metadata from ebook files without altering them. It is a pure read operation with no capability to modify, execute code, delete data, or incur financial consequences. The blast radius of misuse is minimal—an attacker could learn bibliographic information about stored ebooks but cannot modify or destroy them.

From the tool's definition Tool name is 'read_file_metadata' and description states 'Read metadata directly from the ebook file itself'. The verb 'read' and 'read metadata' clearly indicate data retrieval with no modification or side effects.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs read_file_metadata safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Calibre, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For read_file_metadata, this is the rule to start with:

read_file_metadata Allowed

read_file_metadata is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "read_file_metadata": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Calibre, apply this rule, and every read_file_metadata call is checked against it from then on.

FAQ

Questions about read_file_metadata

What does the read_file_metadata tool do? +

Read metadata directly from the ebook file itself (EPUB, MOBI, etc.). It is categorised as a Read tool in the Calibre MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on read_file_metadata? +

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

What risk level is read_file_metadata? +

read_file_metadata is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit read_file_metadata? +

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

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

read_file_metadata is provided by the Calibre MCP server (2b3pro/calibre-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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