From 778039c8794cd2f4abffb68546387fc1141a15f3 Mon Sep 17 00:00:00 2001
From: Niels Kaspers <kaspersniels@gmail.com>
Date: Fri, 13 Mar 2026 09:12:42 +0200
Subject: [PATCH] feat(everything): add tool annotations to all 18 tools

The server-everything reference server is the primary example developers
use to learn MCP. Adding tool annotations brings it in line with
server-filesystem, which already annotates all its tools.

Annotations per tool:
- Read-only tools (echo, get-env, get-sum, etc.): readOnlyHint: true
- Toggle tools: readOnlyHint: false, destructiveHint: false, idempotentHint: false
- gzip-file-as-resource: readOnlyHint: false, idempotentHint: true, openWorldHint: true
- Sampling/elicitation tools: readOnlyHint: false, destructiveHint: false

Fixes #3401
---
 src/everything/tools/echo.ts                              | 1 +
 src/everything/tools/get-annotated-message.ts             | 1 +
 src/everything/tools/get-env.ts                           | 1 +
 src/everything/tools/get-resource-links.ts                | 1 +
 src/everything/tools/get-resource-reference.ts            | 1 +
 src/everything/tools/get-roots-list.ts                    | 1 +
 src/everything/tools/get-structured-content.ts            | 1 +
 src/everything/tools/get-sum.ts                           | 1 +
 src/everything/tools/get-tiny-image.ts                    | 1 +
 src/everything/tools/gzip-file-as-resource.ts             | 1 +
 src/everything/tools/simulate-research-query.ts           | 1 +
 src/everything/tools/toggle-simulated-logging.ts          | 1 +
 src/everything/tools/toggle-subscriber-updates.ts         | 1 +
 src/everything/tools/trigger-elicitation-request-async.ts | 1 +
 src/everything/tools/trigger-elicitation-request.ts       | 1 +
 src/everything/tools/trigger-long-running-operation.ts    | 1 +
 src/everything/tools/trigger-sampling-request-async.ts    | 1 +
 src/everything/tools/trigger-sampling-request.ts          | 1 +
 18 files changed, 18 insertions(+)

diff --git a/src/everything/tools/echo.ts b/src/everything/tools/echo.ts
index 204a2fb49b..df24fcfac7 100644
--- a/src/everything/tools/echo.ts
+++ b/src/everything/tools/echo.ts
@@ -13,6 +13,7 @@ const config = {
   title: "Echo Tool",
   description: "Echoes back the input string",
   inputSchema: EchoSchema,
+  annotations: { readOnlyHint: true },
 };
 
 /**
diff --git a/src/everything/tools/get-annotated-message.ts b/src/everything/tools/get-annotated-message.ts
index ead0660e8f..ba4da94c68 100644
--- a/src/everything/tools/get-annotated-message.ts
+++ b/src/everything/tools/get-annotated-message.ts
@@ -21,6 +21,7 @@ const config = {
   description:
     "Demonstrates how annotations can be used to provide metadata about content.",
   inputSchema: GetAnnotatedMessageSchema,
+  annotations: { readOnlyHint: true },
 };
 
 /**
diff --git a/src/everything/tools/get-env.ts b/src/everything/tools/get-env.ts
index 0adbf5a14d..6e75f98f86 100644
--- a/src/everything/tools/get-env.ts
+++ b/src/everything/tools/get-env.ts
@@ -8,6 +8,7 @@ const config = {
   description:
     "Returns all environment variables, helpful for debugging MCP server configuration",
   inputSchema: {},
+  annotations: { readOnlyHint: true },
 };
 
 /**
diff --git a/src/everything/tools/get-resource-links.ts b/src/everything/tools/get-resource-links.ts
index b1fc627e20..767f6e71ab 100644
--- a/src/everything/tools/get-resource-links.ts
+++ b/src/everything/tools/get-resource-links.ts
@@ -25,6 +25,7 @@ const config = {
   description:
     "Returns up to ten resource links that reference different types of resources",
   inputSchema: GetResourceLinksSchema,
+  annotations: { readOnlyHint: true },
 };
 
 /**
diff --git a/src/everything/tools/get-resource-reference.ts b/src/everything/tools/get-resource-reference.ts
index d3dc5d3ecb..0d0e1721b8 100644
--- a/src/everything/tools/get-resource-reference.ts
+++ b/src/everything/tools/get-resource-reference.ts
@@ -28,6 +28,7 @@ const config = {
   title: "Get Resource Reference Tool",
   description: "Returns a resource reference that can be used by MCP clients",
   inputSchema: GetResourceReferenceSchema,
+  annotations: { readOnlyHint: true },
 };
 
 /**
diff --git a/src/everything/tools/get-roots-list.ts b/src/everything/tools/get-roots-list.ts
index 62363da26a..07602baace 100644
--- a/src/everything/tools/get-roots-list.ts
+++ b/src/everything/tools/get-roots-list.ts
@@ -9,6 +9,7 @@ const config = {
   description:
     "Lists the current MCP roots provided by the client. Demonstrates the roots protocol capability even though this server doesn't access files.",
   inputSchema: {},
+  annotations: { readOnlyHint: true },
 };
 
 /**
diff --git a/src/everything/tools/get-structured-content.ts b/src/everything/tools/get-structured-content.ts
index 83c98c0ab6..f85a5ade09 100644
--- a/src/everything/tools/get-structured-content.ts
+++ b/src/everything/tools/get-structured-content.ts
@@ -27,6 +27,7 @@ const config = {
     "Returns structured content along with an output schema for client data validation",
   inputSchema: GetStructuredContentInputSchema,
   outputSchema: GetStructuredContentOutputSchema,
+  annotations: { readOnlyHint: true },
 };
 
 /**
diff --git a/src/everything/tools/get-sum.ts b/src/everything/tools/get-sum.ts
index 522043c88f..8c25e78cb5 100644
--- a/src/everything/tools/get-sum.ts
+++ b/src/everything/tools/get-sum.ts
@@ -14,6 +14,7 @@ const config = {
   title: "Get Sum Tool",
   description: "Returns the sum of two numbers",
   inputSchema: GetSumSchema,
+  annotations: { readOnlyHint: true },
 };
 
 /**
diff --git a/src/everything/tools/get-tiny-image.ts b/src/everything/tools/get-tiny-image.ts
index 720707d0ce..3de892ea74 100644
--- a/src/everything/tools/get-tiny-image.ts
+++ b/src/everything/tools/get-tiny-image.ts
@@ -11,6 +11,7 @@ const config = {
   title: "Get Tiny Image Tool",
   description: "Returns a tiny MCP logo image.",
   inputSchema: {},
+  annotations: { readOnlyHint: true },
 };
 
 /**
diff --git a/src/everything/tools/gzip-file-as-resource.ts b/src/everything/tools/gzip-file-as-resource.ts
index 608fcf4a0d..8922a1410e 100644
--- a/src/everything/tools/gzip-file-as-resource.ts
+++ b/src/everything/tools/gzip-file-as-resource.ts
@@ -48,6 +48,7 @@ const config = {
   description:
     "Compresses a single file using gzip compression. Depending upon the selected output type, returns either the compressed data as a gzipped resource or a resource link, allowing it to be downloaded in a subsequent request during the current session.",
   inputSchema: GZipFileAsResourceSchema,
+  annotations: { readOnlyHint: false, idempotentHint: true, openWorldHint: true },
 };
 
 /**
diff --git a/src/everything/tools/simulate-research-query.ts b/src/everything/tools/simulate-research-query.ts
index 8b485ca2ba..883d45ba57 100644
--- a/src/everything/tools/simulate-research-query.ts
+++ b/src/everything/tools/simulate-research-query.ts
@@ -254,6 +254,7 @@ export const registerSimulateResearchQueryTool = (server: McpServer) => {
         "Demonstrates MCP task-based operations with progress through multiple stages. " +
         "If 'ambiguous' is true and client supports elicitation, sends an elicitation request for clarification.",
       inputSchema: SimulateResearchQuerySchema,
+      annotations: { readOnlyHint: true },
       execution: { taskSupport: "required" },
     },
     {
diff --git a/src/everything/tools/toggle-simulated-logging.ts b/src/everything/tools/toggle-simulated-logging.ts
index 4941ed77d0..e71b4fc2ca 100644
--- a/src/everything/tools/toggle-simulated-logging.ts
+++ b/src/everything/tools/toggle-simulated-logging.ts
@@ -11,6 +11,7 @@ const config = {
   title: "Toggle Simulated Logging",
   description: "Toggles simulated, random-leveled logging on or off.",
   inputSchema: {},
+  annotations: { readOnlyHint: false, destructiveHint: false, idempotentHint: false },
 };
 
 // Track enabled clients by session id
diff --git a/src/everything/tools/toggle-subscriber-updates.ts b/src/everything/tools/toggle-subscriber-updates.ts
index 03b949e232..9fb1e36044 100644
--- a/src/everything/tools/toggle-subscriber-updates.ts
+++ b/src/everything/tools/toggle-subscriber-updates.ts
@@ -11,6 +11,7 @@ const config = {
   title: "Toggle Subscriber Updates",
   description: "Toggles simulated resource subscription updates on or off.",
   inputSchema: {},
+  annotations: { readOnlyHint: false, destructiveHint: false, idempotentHint: false },
 };
 
 // Track enabled clients by session id
diff --git a/src/everything/tools/trigger-elicitation-request-async.ts b/src/everything/tools/trigger-elicitation-request-async.ts
index 6cf6f3e581..6ecac21e8d 100644
--- a/src/everything/tools/trigger-elicitation-request-async.ts
+++ b/src/everything/tools/trigger-elicitation-request-async.ts
@@ -11,6 +11,7 @@ const config = {
     "Demonstrates bidirectional MCP tasks where the server sends an elicitation request and " +
     "the client handles user input asynchronously, allowing the server to poll for completion.",
   inputSchema: {},
+  annotations: { readOnlyHint: false, destructiveHint: false },
 };
 
 // Poll interval in milliseconds
diff --git a/src/everything/tools/trigger-elicitation-request.ts b/src/everything/tools/trigger-elicitation-request.ts
index 4de7993e9a..8d9da7261e 100644
--- a/src/everything/tools/trigger-elicitation-request.ts
+++ b/src/everything/tools/trigger-elicitation-request.ts
@@ -10,6 +10,7 @@ const config = {
   title: "Trigger Elicitation Request Tool",
   description: "Trigger a Request from the Server for User Elicitation",
   inputSchema: {},
+  annotations: { readOnlyHint: false, destructiveHint: false },
 };
 
 /**
diff --git a/src/everything/tools/trigger-long-running-operation.ts b/src/everything/tools/trigger-long-running-operation.ts
index 8af45ce60b..90776350e5 100644
--- a/src/everything/tools/trigger-long-running-operation.ts
+++ b/src/everything/tools/trigger-long-running-operation.ts
@@ -17,6 +17,7 @@ const config = {
   title: "Trigger Long Running Operation Tool",
   description: "Demonstrates a long running operation with progress updates.",
   inputSchema: TriggerLongRunningOperationSchema,
+  annotations: { readOnlyHint: true },
 };
 
 /**
diff --git a/src/everything/tools/trigger-sampling-request-async.ts b/src/everything/tools/trigger-sampling-request-async.ts
index 2e9fad96bc..e7ce922afb 100644
--- a/src/everything/tools/trigger-sampling-request-async.ts
+++ b/src/everything/tools/trigger-sampling-request-async.ts
@@ -23,6 +23,7 @@ const config = {
     "Demonstrates bidirectional MCP tasks where the server sends a request and the client " +
     "executes it asynchronously, allowing the server to poll for progress and results.",
   inputSchema: TriggerSamplingRequestAsyncSchema,
+  annotations: { readOnlyHint: false, destructiveHint: false },
 };
 
 // Poll interval in milliseconds
diff --git a/src/everything/tools/trigger-sampling-request.ts b/src/everything/tools/trigger-sampling-request.ts
index 5785f5210f..61aa231421 100644
--- a/src/everything/tools/trigger-sampling-request.ts
+++ b/src/everything/tools/trigger-sampling-request.ts
@@ -21,6 +21,7 @@ const config = {
   title: "Trigger Sampling Request Tool",
   description: "Trigger a Request from the Server for LLM Sampling",
   inputSchema: TriggerSamplingRequestSchema,
+  annotations: { readOnlyHint: false, destructiveHint: false },
 };
 
 /**