diff --git a/server.mjs b/server.mjs
index a7aa890..d61dd8a 100644
--- a/server.mjs
+++ b/server.mjs
@@ -455,24 +455,11 @@ function registerHandlers(srv) {
       },
       {
         name: 'upload_image',
-        description:
-          'Upload a reference image to the server for use in image_urls. ' +
-          'Accepts a base64 data URL (e.g. "data:image/png;base64,iVBOR...") or ' +
-          'an HTTP(S) URL. Returns a download_url that can be passed to generate_image ' +
-          'or generate_image_transparent as image_urls entry. ' +
-          'The uploaded file persists only while the container is alive.',
+        description: 'Upload an image to use as reference. Returns a URL for image_urls.',
         inputSchema: {
           type: 'object',
           properties: {
-            data: {
-              type: 'string',
-              description: 'Base64-encoded image data (raw base64 string, not including data: URI prefix) OR a full data:image URL OR an http(s):// URL to fetch.',
-            },
-            filename: {
-              type: 'string',
-              description: 'Optional filename hint (e.g. "ref.png"). Auto-generated if omitted.',
-              default: '',
-            },
+            data: { type: 'string', description: 'base64 image data (with or without data: URI prefix)' },
           },
           required: ['data'],
         },