set_reading_goal · Hardcover MCP: Risk & Policy

WHAT IT DOES

What set_reading_goal does on Hardcover

AI agents use set_reading_goal 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 set_reading_goal needs a policy

This tool creates or updates reading goal metadata (target, metric, dates) in the user's library. These are reversible data modifications—the goal can be changed or deleted later—with no side effects beyond updating the user's own reading preferences. It falls squarely into the Write category (reversible data modification) rather than Read (query-only) or Execute (external operations).

From the tool's definition Tool description states 'Create or update a reading goal', indicating it modifies user data (reading goals) reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_reading_goal Rate-limited

set_reading_goal 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": {
    "set_reading_goal": {
      "limits": [
        {
          "counter": "set_reading_goal_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 set_reading_goal

What does the set_reading_goal tool do? +

Create or update a reading goal with target, metric, dates, and optional. 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 set_reading_goal? +

Register the Hardcover MCP server in PolicyLayer and add a rule for set_reading_goal: 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 set_reading_goal? +

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

Can I rate-limit set_reading_goal? +

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

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

set_reading_goal 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.