diff --git a/rust/crates/api/src/providers/mod.rs b/rust/crates/api/src/providers/mod.rs
index 1584ed3a..7e503410 100644
--- a/rust/crates/api/src/providers/mod.rs
+++ b/rust/crates/api/src/providers/mod.rs
@@ -701,6 +701,8 @@ pub fn model_token_limit(model: &str) -> Option<ModelTokenLimit> {
             max_output_tokens: 8_192,
             context_window_tokens: 131_072,
         }),
+        // Unknown models return None so preflight skips the context-window
+        // check and lets the API enforce its own limits.
         _ => None,
     }
 }