update_user_book_read · Hardcover MCP: Risk & Policy

WHAT IT DOES

What update_user_book_read does on Hardcover

AI agents use update_user_book_read to create or update resources in Hardcover — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Hardcover environment.

WHY IT NEEDS A POLICY

Why update_user_book_read needs a policy

This tool updates existing reading progress records rather than creating new ones or deleting them. Updates are reversible modifications that preserve unspecified fields, making it a Write operation. Severity is medium because misuse could corrupt reading history or progress tracking, but the blast radius is limited to a single user's reading data without financial or permanent consequences.

From the tool's definition Tool name contains 'update' and description states 'Update a reading date or progress entry.' This modifies user data (reading progress) reversibly without deleting it.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_user_book_read Rate-limited

update_user_book_read stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "update_user_book_read": {
      "limits": [
        {
          "counter": "update_user_book_read_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Hardcover, so you can run agents against it safely.

FAQ

Questions about update_user_book_read

What does the update_user_book_read tool do? +

Update a reading date or progress entry. Preserves unspecified fields. It is categorised as a Write tool in the Hardcover MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_user_book_read? +

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

What risk level is update_user_book_read? +

update_user_book_read is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit update_user_book_read? +

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

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

update_user_book_read is provided by the Hardcover MCP server (kristianedlund/hardcover-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.