diff --git a/docs/tasks/streams.mdx b/docs/tasks/streams.mdx
index 57ad8ce6f..ba83bdf05 100644
--- a/docs/tasks/streams.mdx
+++ b/docs/tasks/streams.mdx
@@ -687,7 +687,7 @@ Validation errors use these exact messages:
 
 - `baseURL must not be empty`
 - `baseURL must be a valid absolute URL`
-- `baseURL must not contain internal whitespace characters`
+- `baseURL must not contain internal whitespace characters (including invisible separators)`
 - `baseURL must use http or https protocol`
 - `baseURL must not include query parameters or hash fragments`
 - `baseURL must not include username or password credentials`
diff --git a/packages/ai/README.md b/packages/ai/README.md
index c643916d5..465c13696 100644
--- a/packages/ai/README.md
+++ b/packages/ai/README.md
@@ -194,7 +194,7 @@ Validation errors use these exact messages:
 
 - `baseURL must not be empty`
 - `baseURL must be a valid absolute URL`
-- `baseURL must not contain internal whitespace characters`
+- `baseURL must not contain internal whitespace characters (including invisible separators)`
 - `baseURL must use http or https protocol`
 - `baseURL must not include query parameters or hash fragments`
 - `baseURL must not include username or password credentials`