Improve claude tools (#36538)

- Return unified diff from `Edit` tool so model can see the final state
- Format on save if enabled
- Provide `Write` tool
- Disable `MultiEdit` tool
- Better prompting

Release Notes:

- N/A

crates/agent_servers/src/claude/tools.rs

@@ -34,6 +34,7 @@ impl ClaudeTool {
             // Known tools
             "mcp__zed__Read" => Self::ReadFile(serde_json::from_value(input).log_err()),
             "mcp__zed__Edit" => Self::Edit(serde_json::from_value(input).log_err()),
+            "mcp__zed__Write" => Self::Write(serde_json::from_value(input).log_err()),
             "MultiEdit" => Self::MultiEdit(serde_json::from_value(input).log_err()),
             "Write" => Self::Write(serde_json::from_value(input).log_err()),
             "LS" => Self::Ls(serde_json::from_value(input).log_err()),
@@ -93,7 +94,7 @@ impl ClaudeTool {
             }
             Self::MultiEdit(None) => "Multi Edit".into(),
             Self::Write(Some(params)) => {
-                format!("Write {}", params.file_path.display())
+                format!("Write {}", params.abs_path.display())
             }
             Self::Write(None) => "Write".into(),
             Self::Glob(Some(params)) => {
@@ -153,7 +154,7 @@ impl ClaudeTool {
             }],
             Self::Write(Some(params)) => vec![acp::ToolCallContent::Diff {
                 diff: acp::Diff {
-                    path: params.file_path.clone(),
+                    path: params.abs_path.clone(),
                     old_text: None,
                     new_text: params.content.clone(),
                 },
@@ -229,7 +230,10 @@ impl ClaudeTool {
                     line: None,
                 }]
             }
-            Self::Write(Some(WriteToolParams { file_path, .. })) => {
+            Self::Write(Some(WriteToolParams {
+                abs_path: file_path,
+                ..
+            })) => {
                 vec![acp::ToolCallLocation {
                     path: file_path.clone(),
                     line: None,
@@ -302,6 +306,20 @@ impl ClaudeTool {
     }
 }
 
+/// Edit a file.
+///
+/// In sessions with mcp__zed__Edit always use it instead of Edit as it will
+/// allow the user to conveniently review changes.
+///
+/// File editing instructions:
+/// - The `old_text` param must match existing file content, including indentation.
+/// - The `old_text` param must come from the actual file, not an outline.
+/// - The `old_text` section must not be empty.
+/// - Be minimal with replacements:
+///     - For unique lines, include only those lines.
+///     - For non-unique lines, include enough context to identify them.
+/// - Do not escape quotes, newlines, or other characters.
+/// - Only edit the specified file.
 #[derive(Deserialize, JsonSchema, Debug)]
 pub struct EditToolParams {
     /// The absolute path to the file to read.
@@ -312,6 +330,11 @@ pub struct EditToolParams {
     pub new_text: String,
 }
 
+/// Reads the content of the given file in the project.
+///
+/// Never attempt to read a path that hasn't been previously mentioned.
+///
+/// In sessions with mcp__zed__Read always use it instead of Read as it contains the most up-to-date contents.
 #[derive(Deserialize, JsonSchema, Debug)]
 pub struct ReadToolParams {
     /// The absolute path to the file to read.
@@ -324,11 +347,15 @@ pub struct ReadToolParams {
     pub limit: Option<u32>,
 }
 
+/// Writes content to the specified file in the project.
+///
+/// In sessions with mcp__zed__Write always use it instead of Write as it will
+/// allow the user to conveniently review changes.
 #[derive(Deserialize, JsonSchema, Debug)]
 pub struct WriteToolParams {
-    /// Absolute path for new file
-    pub file_path: PathBuf,
-    /// File content
+    /// The absolute path of the file to write.
+    pub abs_path: PathBuf,
+    /// The full content to write.
     pub content: String,
 }