extract_themes

THE RISK

Low Risk

Why extract_themes needs a policy

extract_themes performs content analysis and categorization without creating, modifying, deleting, or executing anything. It reads manuscript data and returns thematic clustering—a classic Read category operation. The server's purpose is writing assistance through analysis, not modification or execution of external operations.

From the tool's definition Tool description states 'Cluster content into main themes/topics' - a pure analysis/retrieval operation with no modification or execution of external code.

Documented attack patterns abuse exactly the kind of access extract_themes gives an agent:

POLICY

How to control extract_themes

PolicyLayer is an MCP gateway — it sits between your AI agents and Claude Writer's Aid MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for extract_themes:

policy.json

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

extract_themes is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register Claude Writer's Aid MCP — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

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All 34 Claude Writer's Aid MCP tools →

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Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about extract_themes

What does the extract_themes tool do? +

Cluster content into main themes/topics. It is categorised as a Read tool in the Claude Writer's Aid MCP MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on extract_themes? +

Register the Claude Writer's Aid MCP server in PolicyLayer and add a rule for extract_themes: 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 Claude Writer's Aid MCP. Nothing to install.

What risk level is extract_themes? +

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

Can I rate-limit extract_themes? +

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

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

extract_themes is provided by the Claude Writer's Aid MCP server (xiaolai/claude-writers-aid-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Claude Writer's Aid MCP tool call.

Start from Claude Writer's Aid MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →