diff --git a/.env.example b/.env.example
index 609cb1e1..540d1d07 100644
--- a/.env.example
+++ b/.env.example
@@ -272,6 +272,11 @@ ANTHROPIC_API_KEY=sk-ant-your-key-here
 # trigger "Extra required key ... supplied" errors from OpenAI-compatible endpoints
 # OPENCLAUDE_DISABLE_STRICT_TOOLS=1
 
+# Disable hidden <system-reminder> messages injected into tool output
+# Suppresses the file-read cyber-risk reminder and the todo/task tool nudges
+# Useful for users who want full transparency over what the model sees
+# OPENCLAUDE_DISABLE_TOOL_REMINDERS=1
+
 # Custom timeout for API requests in milliseconds (default: varies)
 # API_TIMEOUT_MS=60000
 
diff --git a/src/tools/FileReadTool/FileReadTool.ts b/src/tools/FileReadTool/FileReadTool.ts
index 1ceed46d..90781ef6 100644
--- a/src/tools/FileReadTool/FileReadTool.ts
+++ b/src/tools/FileReadTool/FileReadTool.ts
@@ -733,6 +733,9 @@ export const CYBER_RISK_MITIGATION_REMINDER =
 const MITIGATION_EXEMPT_MODELS = new Set(['claude-opus-4-6'])
 
 function shouldIncludeFileReadMitigation(): boolean {
+  if (isEnvTruthy(process.env.OPENCLAUDE_DISABLE_TOOL_REMINDERS)) {
+    return false
+  }
   const shortName = getCanonicalName(getMainLoopModel())
   return !MITIGATION_EXEMPT_MODELS.has(shortName)
 }
diff --git a/src/utils/messages.ts b/src/utils/messages.ts
index edc33ebd..0597fd86 100644
--- a/src/utils/messages.ts
+++ b/src/utils/messages.ts
@@ -75,6 +75,7 @@ import type {
 import { isAdvisorBlock } from './advisor.js'
 import { isAgentSwarmsEnabled } from './agentSwarmsEnabled.js'
 import { count } from './array.js'
+import { isEnvTruthy } from './envUtils.js'
 import {
   type Attachment,
   type HookAttachment,
@@ -3666,6 +3667,9 @@ Read the team config to discover your teammates' names. Check the task list peri
       ])
     }
     case 'todo_reminder': {
+      if (isEnvTruthy(process.env.OPENCLAUDE_DISABLE_TOOL_REMINDERS)) {
+        return []
+      }
       const todoItems = attachment.content
         .map((todo, index) => `${index + 1}. [${todo.status}] ${todo.content}`)
         .join('\n')
@@ -3686,6 +3690,9 @@ Read the team config to discover your teammates' names. Check the task list peri
       if (!isTodoV2Enabled()) {
         return []
       }
+      if (isEnvTruthy(process.env.OPENCLAUDE_DISABLE_TOOL_REMINDERS)) {
+        return []
+      }
       const taskItems = attachment.content
         .map(task => `#${task.id}. [${task.status}] ${task.subject}`)
         .join('\n')