crow_calibre_list_categories

List available categories in the Calibre library (authors, tags, series, publishers, languages, ratings)

SERVERCrow SOURCEkh0pper/crow

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/kh0pper-crow/crow-calibre-list-categories.md

WHAT IT DOES

What crow_calibre_list_categories does on Crow

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

RISK

Why crow_calibre_list_categories is rated Low

This tool performs a read-only enumeration of library metadata. It retrieves information without creating, modifying, deleting, or executing any operations. The blast radius of misuse is minimal—an attacker gains only visibility into library structure, not access to books, user data, or system control.

From the tool's definition Tool name contains 'list' and description states 'List available categories' — a query operation that retrieves metadata (authors, tags, series, publishers, languages, ratings) from a Calibre library with no modification or side effects.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs crow_calibre_list_categories safely

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

crow_calibre_list_categories Allowed

crow_calibre_list_categories 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": {
    "crow_calibre_list_categories": {}
  }
}

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

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

FAQ

Questions about crow_calibre_list_categories

What does the crow_calibre_list_categories tool do? +

List available categories in the Calibre library (authors, tags, series, publishers, languages, ratings). It is categorised as a Read tool in the Crow MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on crow_calibre_list_categories? +

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

What risk level is crow_calibre_list_categories? +

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

Can I rate-limit crow_calibre_list_categories? +

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

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

crow_calibre_list_categories is provided by the Crow MCP server (kh0pper/crow). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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