Rename read_file to read_text_file and add read_media_file

src/filesystem/README.md

@@ -70,10 +70,18 @@ The server's directory access control follows this flow:
 
 ### Tools
 
-- **read_file**
-  - Read complete contents of a file
+- **read_text_file**
+  - Read complete contents of a file as text
+  - Inputs:
+    - `path` (string)
+    - `head` (number, optional): First N lines
+    - `tail` (number, optional): Last N lines
+  - Always treats the file as UTF-8 text regardless of extension
+
+- **read_media_file**
+  - Read an image or audio file
   - Input: `path` (string)
-  - Reads complete file contents with UTF-8 encoding
+  - Returns base64 data and MIME type based on the file extension
 
 - **read_multiple_files**
   - Read multiple files simultaneously