diff --git a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Contact.kt b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Contact.kt
index 33350b226..671fb63e8 100644
--- a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Contact.kt
+++ b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Contact.kt
@@ -54,6 +54,8 @@ actual abstract class Contact : CoroutineScope, ContactJavaFriendlyAPI() {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/ContactJavaFriendlyAPI.kt b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/ContactJavaFriendlyAPI.kt
index 14b67b214..98cca8d5b 100644
--- a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/ContactJavaFriendlyAPI.kt
+++ b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/ContactJavaFriendlyAPI.kt
@@ -48,6 +48,8 @@ actual abstract class ContactJavaFriendlyAPI {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Group.kt b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Group.kt
index 141835287..e7a2f04f3 100644
--- a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Group.kt
+++ b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Group.kt
@@ -125,6 +125,8 @@ actual abstract class Group : Contact(), CoroutineScope {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Member.kt b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Member.kt
index 7ae76a4ea..2f490a8f5 100644
--- a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Member.kt
+++ b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/Member.kt
@@ -110,6 +110,8 @@ actual abstract class Member : MemberJavaFriendlyAPI() {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/QQ.kt b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/QQ.kt
index 16c623883..034bd8415 100644
--- a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/QQ.kt
+++ b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/contact/QQ.kt
@@ -78,6 +78,8 @@ actual abstract class QQ : Contact(), CoroutineScope {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Contact.kt b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Contact.kt
index 41e2d4b5d..30c0366a5 100644
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Contact.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Contact.kt
@@ -57,6 +57,8 @@ expect abstract class Contact() : CoroutineScope, ContactJavaFriendlyAPI {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Group.kt b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Group.kt
index cbf96ee27..992741e79 100644
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Group.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Group.kt
@@ -129,6 +129,8 @@ expect abstract class Group() : Contact, CoroutineScope {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Member.kt b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Member.kt
index faab5e7ea..60f4ce045 100644
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Member.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Member.kt
@@ -132,6 +132,8 @@ expect abstract class Member() : MemberJavaFriendlyAPI {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see MessageSendEvent.FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see MessageSendEvent.GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/QQ.kt b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/QQ.kt
index 81956420e..1e3433e19 100644
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/QQ.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/QQ.kt
@@ -87,6 +87,8 @@ expect abstract class QQ() : Contact, CoroutineScope {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Contact.kt b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Contact.kt
index 037f95db2..627acd8ed 100644
--- a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Contact.kt
+++ b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Contact.kt
@@ -53,6 +53,8 @@ actual abstract class Contact : CoroutineScope, ContactJavaFriendlyAPI() {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/ContactJavaFriendlyAPI.kt b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/ContactJavaFriendlyAPI.kt
index 8bf1de8c2..015e4cf82 100644
--- a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/ContactJavaFriendlyAPI.kt
+++ b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/ContactJavaFriendlyAPI.kt
@@ -48,6 +48,8 @@ actual abstract class ContactJavaFriendlyAPI {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Group.kt b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Group.kt
index 0ed79ab31..5caa0266e 100644
--- a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Group.kt
+++ b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Group.kt
@@ -127,6 +127,8 @@ actual abstract class Group : Contact(), CoroutineScope {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Member.kt b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Member.kt
index 2d585bbbc..abd3d9249 100644
--- a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Member.kt
+++ b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/Member.kt
@@ -118,6 +118,8 @@ actual abstract class Member : MemberJavaFriendlyAPI() {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *
diff --git a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/QQ.kt b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/QQ.kt
index 16c623883..034bd8415 100644
--- a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/QQ.kt
+++ b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/contact/QQ.kt
@@ -78,6 +78,8 @@ actual abstract class QQ : Contact(), CoroutineScope {
     /**
      * 向这个对象发送消息.
      *
+     * 单条消息最大可发送 4500 字符或 50 张图片.
+     *
      * @see FriendMessageSendEvent 发送好友信息事件, cancellable
      * @see GroupMessageSendEvent  发送群消息事件. cancellable
      *