diff --git a/src/agent.rs b/src/agent.rs
index 1475a4f..097281d 100644
--- a/src/agent.rs
+++ b/src/agent.rs
@@ -16,6 +16,8 @@ pub enum ToolError {
     Io(#[from] std::io::Error),
     #[error("Command execution failed: {0}")]
     CommandFailed(String),
+    #[error("Invalid line range: {0}")]
+    InvalidLineRange(String),
 }
 
 // Create file tool
@@ -105,6 +107,10 @@ impl Tool for DeleteFileTool {
 #[derive(Deserialize)]
 pub struct ReadFileArgs {
     path: String,
+    #[serde(default)]
+    start_line: Option<usize>,
+    #[serde(default)]
+    end_line: Option<usize>,
 }
 
 #[derive(Serialize, Deserialize)]
@@ -119,13 +125,21 @@ impl Tool for ReadFileTool {
     async fn definition(&self, _prompt: String) -> ToolDefinition {
         ToolDefinition {
             name: Self::NAME.to_string(),
-            description: "Read the content of a file".to_string(),
+            description: "Read the content of a file, optionally with line range".to_string(),
             parameters: json!({
                 "type": "object",
                 "properties": {
                     "path": {
                         "type": "string",
                         "description": "Path of the file to read"
+                    },
+                    "start_line": {
+                        "type": "number",
+                        "description": "Optional: Starting line number (1-based, inclusive)"
+                    },
+                    "end_line": {
+                        "type": "number",
+                        "description": "Optional: Ending line number (1-based, inclusive)"
                     }
                 },
                 "required": ["path"]
@@ -135,8 +149,81 @@ impl Tool for ReadFileTool {
 
     async fn call(&self, args: Self::Args) -> Result<Self::Output, Self::Error> {
         let content = fs::read_to_string(&args.path)?;
-        println!("file content:\n{}", content);
-        Ok(format!("file content:\n{}", content))
+
+        let result = match (args.start_line, args.end_line) {
+            (Some(start), Some(end)) if start > end || start == 0 => {
+                return Err(ToolError::InvalidLineRange(
+                    format!("Invalid range: start={}, end={}", start, end)
+                ));
+            }
+            (Some(start), Some(end)) => {
+                content.lines()
+                    .skip(start.saturating_sub(1))
+                    .take(end - start + 1)
+                    .collect::<Vec<_>>()
+                    .join("\n")
+            }
+            (Some(start), None) => {
+                content.lines()
+                    .skip(start.saturating_sub(1))
+                    .collect::<Vec<_>>()
+                    .join("\n")
+            }
+            (None, Some(end)) => {
+                content.lines()
+                    .take(end)
+                    .collect::<Vec<_>>()
+                    .join("\n")
+            }
+            (None, None) => content,
+        };
+        
+        println!("file content:\n{}", result);
+        Ok(format!("file content:\n{}", result))
+    }
+}
+
+// Edit file tool
+#[derive(Deserialize)]
+pub struct EditFileArgs {
+    path: String,
+    content: String,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct EditFileTool;
+
+impl Tool for EditFileTool {
+    const NAME: &'static str = "edit_file";
+    type Error = ToolError;
+    type Args = EditFileArgs;
+    type Output = String;
+
+    async fn definition(&self, _prompt: String) -> ToolDefinition {
+        ToolDefinition {
+            name: Self::NAME.to_string(),
+            description: "Edit or overwrite an existing file with new content".to_string(),
+            parameters: json!({
+                "type": "object",
+                "properties": {
+                    "path": {
+                        "type": "string",
+                        "description": "Path of the file to edit"
+                    },
+                    "content": {
+                        "type": "string",
+                        "description": "New content to write to the file"
+                    }
+                },
+                "required": ["path", "content"]
+            }),
+        }
+    }
+
+    async fn call(&self, args: Self::Args) -> Result<Self::Output, Self::Error> {
+        fs::write(&args.path, &args.content)?;
+        println!("file edited: {}", args.path);
+        Ok(format!("file edited: {}", args.path))
     }
 }
 
diff --git a/src/main.rs b/src/main.rs
index d275748..e8bbb33 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -26,6 +26,7 @@ async fn main() {
         .tool(agent::CreateFileTool)
         .tool(agent::DeleteFileTool)
         .tool(agent::ReadFileTool)
+        .tool(agent::EditFileTool)
         .tool(agent::ExecuteCommandTool)
         .build();