diff --git a/docs/mcp.md b/docs/mcp.md
index 7da2ffb3b..9785365fe 100644
--- a/docs/mcp.md
+++ b/docs/mcp.md
@@ -56,8 +56,8 @@ folders:
   its nearest existing folder's links are followed and the rest must be plain names, so `..` below a
   folder that doesn't exist is refused, as is a link that leads nowhere (writing through it would
   create its target). The result is compared with the root by whole folder names: `/work2/x` is not
-  inside `/work`. On Windows case is ignored, UNC paths (`\\server\share\...`) are resolved like
-  drive-letter ones, and device names (`CON`, `NUL`, `COM1`...) are refused.
+  inside `/work`. On Windows names are compared exactly after what exists is resolved to its real case (so `OUT\\x` reaches the root `out` on an ordinary volume, but not in a case-sensitive folder), UNC paths (`\\server\share\...`) are resolved like
+  drive-letter ones, and device names (`CON`, `NUL`, `COM1`, `COM¹`..., also followed by an extension or a colon) are refused.
 - A refused path is an ordinary tool error the agent can read and correct, for example
   `automation path rejected: outside the write root /work/project/out: /etc/x.pptx` or
   `automation filesystem access is not granted: write authority is absent: /work/project/out/x.pptx`.