diff --git a/README.md b/README.md
index bd4789d7a..92f56786f 100644
--- a/README.md
+++ b/README.md
@@ -5,25 +5,27 @@
 
 - [Overview](#overview)
 - [Installation](#installation)
-- [Quickstart](#quick-start)
-- [What is MCP?](#what-is-mcp)
+- [Quick Start](#quick-start)
 - [Core Concepts](#core-concepts)
     - [Server](#server)
-    - [Resources](#resources)
     - [Tools](#tools)
+    - [Resources](#resources)
     - [Prompts](#prompts)
     - [Completions](#completions)
+    - [Display Names and Metadata](#display-names-and-metadata)
     - [Sampling](#sampling)
 - [Running Your Server](#running-your-server)
-    - [stdio](#stdio)
     - [Streamable HTTP](#streamable-http)
+    - [stdio](#stdio)
     - [Testing and Debugging](#testing-and-debugging)
 - [Examples](#examples)
     - [Echo Server](#echo-server)
     - [SQLite Explorer](#sqlite-explorer)
 - [Advanced Usage](#advanced-usage)
     - [Dynamic Servers](#dynamic-servers)
+    - [Improving Network Efficiency with Notification Debouncing](#improving-network-efficiency-with-notification-debouncing)
     - [Low-Level Server](#low-level-server)
+    - [Eliciting User Input](#eliciting-user-input)
     - [Writing MCP Clients](#writing-mcp-clients)
     - [Proxy Authorization Requests Upstream](#proxy-authorization-requests-upstream)
     - [Backwards Compatibility](#backwards-compatibility)
diff --git a/package-lock.json b/package-lock.json
index 4a2dc15d2..4c5deb6f7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
     "name": "@modelcontextprotocol/sdk",
-    "version": "1.20.0",
+    "version": "1.20.1",
     "lockfileVersion": 3,
     "requires": true,
     "packages": {
         "": {
             "name": "@modelcontextprotocol/sdk",
-            "version": "1.20.0",
+            "version": "1.20.1",
             "license": "MIT",
             "dependencies": {
                 "ajv": "^6.12.6",
diff --git a/package.json b/package.json
index ad0db7075..1a5837a51 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@modelcontextprotocol/sdk",
-    "version": "1.20.0",
+    "version": "1.20.1",
     "description": "Model Context Protocol implementation for TypeScript",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",
diff --git a/src/client/auth.test.ts b/src/client/auth.test.ts
index c38f19331..f2dadbb15 100644
--- a/src/client/auth.test.ts
+++ b/src/client/auth.test.ts
@@ -863,7 +863,8 @@ describe('OAuth Authorization', () => {
             const calls = mockFetch.mock.calls;
             const [, options] = calls[0];
             expect(options.headers).toEqual({
-                'MCP-Protocol-Version': '2025-01-01'
+                'MCP-Protocol-Version': '2025-01-01',
+                Accept: 'application/json'
             });
         });
 
diff --git a/src/client/auth.ts b/src/client/auth.ts
index 3c04f7cb5..1e90f34ba 100644
--- a/src/client/auth.ts
+++ b/src/client/auth.ts
@@ -738,7 +738,10 @@ export async function discoverAuthorizationServerMetadata(
         protocolVersion?: string;
     } = {}
 ): Promise<AuthorizationServerMetadata | undefined> {
-    const headers = { 'MCP-Protocol-Version': protocolVersion };
+    const headers = {
+        'MCP-Protocol-Version': protocolVersion,
+        Accept: 'application/json'
+    };
 
     // Get the list of URLs to try
     const urlsToTry = buildDiscoveryUrls(authorizationServerUrl);
diff --git a/src/shared/auth.test.ts b/src/shared/auth.test.ts
index 41f9dc1a9..71877f341 100644
--- a/src/shared/auth.test.ts
+++ b/src/shared/auth.test.ts
@@ -1,5 +1,11 @@
 import { describe, it, expect } from '@jest/globals';
-import { SafeUrlSchema, OAuthMetadataSchema, OpenIdProviderMetadataSchema, OAuthClientMetadataSchema } from './auth.js';
+import {
+    SafeUrlSchema,
+    OAuthMetadataSchema,
+    OpenIdProviderMetadataSchema,
+    OAuthClientMetadataSchema,
+    OptionalSafeUrlSchema
+} from './auth.js';
 
 describe('SafeUrlSchema', () => {
     it('accepts valid HTTPS URLs', () => {
@@ -26,6 +32,12 @@ describe('SafeUrlSchema', () => {
     });
 });
 
+describe('OptionalSafeUrlSchema', () => {
+    it('accepts empty string and transforms it to undefined', () => {
+        expect(OptionalSafeUrlSchema.parse('')).toBe(undefined);
+    });
+});
+
 describe('OAuthMetadataSchema', () => {
     it('validates complete OAuth metadata', () => {
         const metadata = {
diff --git a/src/shared/auth.ts b/src/shared/auth.ts
index 0e079646b..c5ddbda16 100644
--- a/src/shared/auth.ts
+++ b/src/shared/auth.ts
@@ -151,6 +151,11 @@ export const OAuthErrorResponseSchema = z.object({
     error_uri: z.string().optional()
 });
 
+/**
+ * Optional version of SafeUrlSchema that allows empty string for retrocompatibility on tos_uri and logo_uri
+ */
+export const OptionalSafeUrlSchema = SafeUrlSchema.optional().or(z.literal('').transform(() => undefined));
+
 /**
  * RFC 7591 OAuth 2.0 Dynamic Client Registration metadata
  */
@@ -162,10 +167,10 @@ export const OAuthClientMetadataSchema = z
         response_types: z.array(z.string()).optional(),
         client_name: z.string().optional(),
         client_uri: SafeUrlSchema.optional(),
-        logo_uri: SafeUrlSchema.optional(),
+        logo_uri: OptionalSafeUrlSchema,
         scope: z.string().optional(),
         contacts: z.array(z.string()).optional(),
-        tos_uri: SafeUrlSchema.optional(),
+        tos_uri: OptionalSafeUrlSchema,
         policy_uri: z.string().optional(),
         jwks_uri: SafeUrlSchema.optional(),
         jwks: z.any().optional(),