chore: update README and schema for clarity on portal URL usage

Author: BatLeDev

README.md

@@ -1,10 +1,22 @@
-# mcp
+# <img alt="Data FAIR logo" src="https://cdn.jsdelivr.net/gh/data-fair/data-fair@master/ui/public/assets/logo.svg" width="25"> @data-fair/mcp ![GitHub License](https://img.shields.io/github/license/data-fair/mcp) ![GitHub package.json version](https://img.shields.io/github/package-json/v/data-fair/mcp)  
 
-Model Context Protocol (MCP) servers to allow AI agents to interact with the Data Fair ecosystem.
+A Model Context Protocol (MCP) server to interact with the Data Fair ecosystem.
 
-## Environment Variables
+## ⚙️ Environment Variables
 
-- `PORTAL_URL`: URL of the data-fair portal (e.g., `https://opendata.koumoul.com` or `https://data.ademe.fr`).
-- `OBSERVER_ACTIVE`: enable observer (true/false)
-- `PORT`: port for the server to listen on
-- `TRANSPORT`: transport mode (`stdio` or `http`)
+| Variable          | Description                                                                                                                                                                  | Default | Mode         |
+|-------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|--------------|
+| `PORTAL_URL`      | Base URL of the Data Fair portal. If not set and `TRANSPORT=http`, the portal URL is inferred from the request origin. When `TRANSPORT=stdio`, you must set this value.      | —       | http/stdio   |
+| `OBSERVER_ACTIVE` | Enable Prometheus metrics.                                                                                                                                                   | `true`  | http only    |
+| `OBSERVER_PORT`   | Port for the Prometheus metrics observer.                                                                                                                                    | `9090`  | http only    |
+| `PORT`            | Port for the HTTP server to listen on.                                                                                                                                       | `8080`  | http only    |
+| `TRANSPORT`       | Transport mode : `stdio` or `http`                                                                                                                                           | `stdio` | http/stdio   |
+
+Notes:
+
+- In HTTP mode, `PORTAL_URL` is optional (derived from request origin). In stdio mode, it is required.
+- Prometheus metrics (observer) run only in HTTP mode.
+
+## 🔨 Development
+
+Take a look at the [contribution guidelines](./CONTRIBUTING.md).

config/type/schema.json

@@ -20,7 +20,8 @@
   "properties": {
     "portalUrl": {
       "type": "string",
-      "description": "The URL of the portal. By default, in http mode the host of the request is used."
+      "description": "Base URL of the Data Fair portal. If not set and transport=\"http\", the portal URL is inferred from the request origin. When transport=\"stdio\", you must set this value.",
+      "example": "https://opendata.koumoul.com"
     },
     "observer": {
       "type": "object",

package.json

@@ -1,7 +1,7 @@
 {
   "name": "@data-fair/mcp",
   "version": "0.0.0",
-  "description": "Model Context Protocol servers for the Data Fair ecosystem",
+  "description": "A Model Context Protocol server for the Data Fair ecosystem",
   "type": "module",
   "main": "index.ts",
   "scripts": {