diff --git a/content/manuals/ai/sandboxes/governance/concepts.md b/content/manuals/ai/sandboxes/governance/concepts.md
index 469ec5dd7d8..ae2dfa27862 100644
--- a/content/manuals/ai/sandboxes/governance/concepts.md
+++ b/content/manuals/ai/sandboxes/governance/concepts.md
@@ -80,6 +80,10 @@ Both IPv4 and IPv6 notation are supported: `10.0.0.0/8`, `192.168.1.0/24`,
 Filesystem rules use the actions `read` and `write`. Resources are host paths
 that sandboxes can mount as workspaces.
 
+A workspace mounted with write access must be allowed by both a `read` and a
+`write` rule; a read-only workspace needs only `read`. When default deny blocks
+a mount, the denial reason names whether read or write access was missing.
+
 `~` expands to the user's home directory on every platform, including Windows,
 where it resolves to `%USERPROFILE%`. A single `~/**` rule therefore matches
 each user's home tree on macOS, Linux, and Windows. The policy engine expands
diff --git a/content/manuals/ai/sandboxes/governance/monitoring.md b/content/manuals/ai/sandboxes/governance/monitoring.md
index 1df88ada4c7..757e16b8221 100644
--- a/content/manuals/ai/sandboxes/governance/monitoring.md
+++ b/content/manuals/ai/sandboxes/governance/monitoring.md
@@ -27,7 +27,9 @@ kit:my-sandbox:deny   network   sandbox:my-sandbox   deny       active   telemet
 The columns are:
 
 - `NAME`: the rule name.
-- `TYPE`: the rule domain, such as `network`.
+- `TYPE`: the rule domain. Network rules show as `network`. Filesystem rules
+  show as `filesystem:read` or `filesystem:write`, depending on the access the
+  rule controls.
 - `ORIGIN`: where the rule was configured. `local` means the rule is global
   and applies to all sandboxes. `sandbox:<name>` means the rule is scoped to
   the named sandbox. `remote` means the rule was set by your organization.
@@ -80,14 +82,34 @@ allow Docker services network   remote               allow      active     *.doc
 Inactive rules show with an `inactive` status. They have no effect while
 organization governance is active.
 
-Use `--type network` to show only network rules. Without a sandbox argument,
-`sbx policy ls` shows every rule across all sandboxes. Pass a sandbox name to
-filter to global rules and rules scoped to that sandbox:
+Use `--type network` or `--type filesystem` to show only rules of that type.
+Without a sandbox argument, `sbx policy ls` shows every rule across all
+sandboxes. Pass a sandbox name to filter to global rules and rules scoped to
+that sandbox:
 
 ```console
 $ sbx policy ls my-sandbox
 ```
 
+### Filesystem rules
+
+`sbx policy ls` lists filesystem rules alongside network rules. Filesystem
+rules control which host paths a sandbox can mount as a workspace. Pass
+`--type filesystem` to show only them:
+
+```console
+$ sbx policy ls --type filesystem
+NAME                         TYPE              ORIGIN   DECISION   STATUS   RESOURCES
+default-fs-read-allow-all    filesystem:read   local    allow      active   **
+default-fs-write-allow-all   filesystem:write  local    allow      active   **
+```
+
+A writable workspace mount must be allowed by both a `filesystem:read` and a
+`filesystem:write` rule; a read-only mount needs only `filesystem:read`. The
+default local policy allows read and write access to all paths, shown as the
+two `default-fs-*` rules above. For the rule syntax and path patterns, see
+[Policy concepts](concepts.md#filesystem-rules).
+
 ## Monitoring traffic
 
 Use `sbx policy log` to see which hosts your sandboxes have contacted and
@@ -127,3 +149,5 @@ $ sbx policy log my-sandbox
 
 Use `--limit N` to show only the last `N` entries, `--json` for
 machine-readable output, or `--type network` to filter by policy type.
+`sbx policy log` records network traffic only; filesystem mount decisions
+aren't available in the log yet.
diff --git a/content/manuals/ai/sandboxes/governance/org.md b/content/manuals/ai/sandboxes/governance/org.md
index 46e734a056b..1bf089f7947 100644
--- a/content/manuals/ai/sandboxes/governance/org.md
+++ b/content/manuals/ai/sandboxes/governance/org.md
@@ -71,8 +71,8 @@ access to.
 Admins can restrict which paths are mountable with filesystem allow and deny
 rules. Each rule takes a path pattern and an action (allow or deny).
 
-For path pattern syntax including the difference between `*` and `**`, see
-[Policy concepts](concepts.md#filesystem-rules).
+For path pattern syntax and how read and write access combine to allow a
+mount, see [Policy concepts](concepts.md#filesystem-rules).
 
 ## Scope policies to teams