docs: update usage.md slash commands, fix context model description

doc/usage.md

@@ -73,7 +73,7 @@ o <session>/<agent> <cmd>   Agent level
 ```
 
 The slash in `<session>/<agent>` disambiguates session-only from session+agent.
-If no command follows the context, `o` defaults to `ls`.
+`o ls` lists the root of the ollie namespace; `o` with no arguments prints help.
 
 ### Commands
 
@@ -133,14 +133,25 @@ Type . on a blank line to send, Ctrl+D to exit.
 ```
 
 Type your prompt across multiple lines, then send with `.` on its own line.
-Slash commands control the agent without sending a prompt:
+Any agent ctl command works as a slash command — the `/` prefix is stripped
+and the rest is sent to `ctl`:
 
 | Command | Description |
 |---|---|
 | `/stop` | Interrupt running agent |
 | `/compact` | Compact context window |
-| `/model X` | Switch model |
-| `/cwd X` | Change working directory |
+| `/clear` | Clear history |
+| `/kill` | Kill the agent |
+| `/model [X]` | Show or switch model |
+| `/models` | List available models |
+| `/backend` | Show current backend |
+| `/agent [X]` | Show or switch agent profile |
+| `/name [X]` | Show or set agent display name |
+| `/cwd [X]` | Show or change working directory |
+| `/inject X` | Inject text into context (alias: `/i`) |
+| `/tools` | List loaded tools |
+| `/tool_load X` | Load a tool |
+| `/tool_unload X` | Unload a tool |
 | `!q` | Kill the tmux TUI session and exit |
 
 Piped input is also supported: