Worth Sending

Does this adoption message earn the recipient's attention?

Worth Sending is a small MCP server that applies an evidence-based rubric to product-adoption messages. An agent supplies a draft, recipient context, evidence, and its assessment. The server returns send, revise, or hold, with a score and the reasons behind the recommendation.

Created by Userlens. MIT licensed. Runs locally with Node.js 20 or later. No separate model API key, account, database, or hosted service is required.

Release candidate: v0.1.0 is available from the feat/initial-release branch for review. An npm registry release has not been published.

Try it

git clone --branch feat/initial-release https://github.com/wudpecker/worth-sending-mcp.git
cd worth-sending-mcp
npm ci
npm run example

The synthetic weekly-report example returns a recommendation including:

{
  "rubric_version": "0.1",
  "decision": "send",
  "score": 93.75,
  "summary": "All required checks, dimension minimums, and the send threshold pass.",
  "assessment_source": "calling_agent",
  "recommendation_only": true
}

A draft with no recipient context returns hold and score: null:

node bin/worth-sending.js evaluate examples/missing-context.json

Related MCP server: Jev Answer Check

Connect an MCP client

For clients that use an mcpServers JSON configuration, add this entry. Replace the path with the absolute location of your clone:

{
  "mcpServers": {
    "worth-sending": {
      "command": "node",
      "args": ["/absolute/path/to/worth-sending-mcp/bin/worth-sending.js"]
    }
  }
}

If the client does not inherit your shell's PATH, use the absolute path to your Node executable for command. Reload the client's MCP connections after saving.

You can also run the GitHub release candidate through npm, without a manual clone:

{
  "mcpServers": {
    "worth-sending": {
      "command": "npx",
      "args": [
        "--yes",
        "--package=github:wudpecker/worth-sending-mcp#feat/initial-release",
        "worth-sending-mcp"
      ]
    }
  }
}

For reproducibility, replace the branch ref with a reviewed commit SHA. This GitHub install runs local code and installs its npm dependencies. It is not a remote MCP endpoint. Clients that accept only an HTTPS server URL need a future hosted transport; this release supports stdio.

Do not use npx worth-sending-mcp as a registry shortcut yet: this project has not published that npm package.

Ask your agent

Evaluate whether this adoption message is worth sending using Worth Sending. Read get_message_rubric first. Use the context and evidence I provide to judge each check and dimension, then call evaluate_message. Keep unknown facts unknown. Explain the recommendation and what would change it.

Provide the exact draft, recipient's goal and workflow, product eligibility, channel and contact history, expected recipient benefit, intended sender outcome, and source-dated evidence. See the complete synthetic input. The tool can accept an incomplete packet and return the missing context.

How it works

1. get_message_rubric provides the rating anchors and decision policy.

2. Your agent assesses the message using the evidence it has permission to use.

3. evaluate_message validates the packet, checks evidence references, and applies the fixed policy to the agent's judgments.

The same rubric is available as a resource at worth-sending://rubric/v0.1.

The calling agent judges meaning and evidence quality. The server has no built-in LLM and does not independently verify facts or infer intent from a draft. It validates structure, referenced evidence IDs, timestamps, and decision rules. Fabricated evidence can still produce a bad recommendation. A send verdict is a recommendation, not dispatch authorization.

Ratings run from 0 to 4. The weighted total is out of 100. Under this initial policy, 80 or more can receive send; 60–79.99 receives revise when the required minimums pass; lower totals receive hold. Weak actionability can also require revision above 80. Weak recipient value, relevance, timing, or business fit overrides the total and produces hold.

Claims must be supported, the recipient must be eligible, the action must still be needed, delivery must be allowed, and the contact window must be clear. A failed or unknown check—or missing essential context or rating—produces hold with no score. Malformed assessments, nonexistent evidence references, duplicate evidence IDs, future evidence, and gates supported only by inference are rejected as invalid input.

Rubric v0.1 is a hypothesis. The weights are not calibrated predictions of ROI or conversion. Validate them against independent reviews and recipient outcomes, including completed tasks, useful repeat behavior, and dismissals. Use this policy for discretionary adoption nudges; operational or security notices need a different policy. Read the full rubric.

CLI and library

node bin/worth-sending.js --help
node bin/worth-sending.js evaluate examples/weekly-report.json
node bin/worth-sending.js evaluate - < examples/weekly-report.json

Within a clone, the scoring function is also directly importable:

import { evaluateMessage } from './src/evaluate.js';

const result = evaluateMessage(assessmentPacket);

The default executable starts the MCP server and waits for a client on stdin. Use node bin/worth-sending.js in an MCP configuration. If you use npm scripts instead, run npm run --silent start so npm's banner cannot pollute the protocol. The evaluate CLI writes JSON and exits with status 0 for all valid decisions; inspect decision to distinguish send/revise/hold. Invalid input exits with 1.

Data handling

The server does not make outbound requests, log message content, write assessment files, or send messages. Inputs and results travel through your existing MCP client and may be subject to that client's model provider and retention settings. All checked-in examples are synthetic.

Development

npm ci
npm test
npm pack --dry-run

Tests cover policy thresholds and overrides, evidence validation, missing context, MCP discovery and resource reads, structured results, errors, and recovery. See CONTRIBUTING.md and the release guide.

Built with the official MCP SDK. See its stdio client documentation for the local-process connection model.

License

MIT © 2026 Userlens.