diff --git a/crates/openab-core/src/gateway.rs b/crates/openab-core/src/gateway.rs
index caac2441e..1b7575317 100644
--- a/crates/openab-core/src/gateway.rs
+++ b/crates/openab-core/src/gateway.rs
@@ -499,7 +499,10 @@ impl ChatAdapter for GatewayAdapter {
     }
 
     fn message_limit(&self) -> usize {
-        4096 // Telegram limit
+        match self.platform_name {
+            "teams" => 20000, // Teams ~80 KB UTF-16; 20000 BMP chars ≈ 40 KB (safe margin)
+            _ => 4096,        // Telegram / generic limit
+        }
     }
 
     async fn send_message(&self, channel: &ChannelRef, content: &str) -> Result<MessageRef> {
diff --git a/docs/platforms/schema/teams.toml b/docs/platforms/schema/teams.toml
index 42a325e85..364c4398c 100644
--- a/docs/platforms/schema/teams.toml
+++ b/docs/platforms/schema/teams.toml
@@ -126,7 +126,8 @@ pr      = ""
 [[openab_features]]
 feature = "message_split"
 status  = "partial"
-note    = "Core splits via `split_delivery`; `GatewayAdapter::message_limit()` returns 4096 (hardcoded 'Telegram limit', not Teams' ~100 KB / UTF-16 budget) — chunking works but the bound is generic, not Teams-tuned."
+pr      = "#1410"
+note    = "Core splits via `split_delivery`; standalone `GatewayAdapter` returns 20000 for Teams (BMP-char budget ≈ 40 KB UTF-16). Unified Mode remains at 4096 (shared with LINE/Telegram) pending a channel-aware `message_limit_for()` API."
 source  = ["crates/openab-core/src/adapter.rs#message_limit", "crates/openab-core/src/gateway.rs"]
 pr      = ""
 
diff --git a/src/unified_adapter.rs b/src/unified_adapter.rs
index d04d1ba7a..5e7f6c157 100644
--- a/src/unified_adapter.rs
+++ b/src/unified_adapter.rs
@@ -130,7 +130,11 @@ impl ChatAdapter for UnifiedGatewayAdapter {
     }
 
     fn message_limit(&self) -> usize {
-        4096 // conservative limit across platforms
+        // Unified Mode serves multiple platforms (Teams, LINE, Telegram, etc.)
+        // with different limits. Use the most conservative (LINE = 5000,
+        // Telegram = 4096). Platform-specific budgets require a future
+        // channel-aware message_limit_for() API.
+        4096
     }
 
     async fn send_message(&self, channel: &ChannelRef, content: &str) -> Result<MessageRef> {