diff --git a/cli/src/diff_util.rs b/cli/src/diff_util.rs
index 52ded4013..b9b2dc586 100644
--- a/cli/src/diff_util.rs
+++ b/cli/src/diff_util.rs
@@ -38,6 +38,7 @@ use tracing::instrument;
 use unicode_width::UnicodeWidthStr as _;
 
 use crate::cli_util::{CommandError, WorkspaceCommandHelper};
+use crate::config::CommandNameAndArgs;
 use crate::formatter::Formatter;
 use crate::merge_tools::{self, ExternalMergeTool, MergeTool};
 use crate::text_util;
@@ -144,8 +145,12 @@ fn default_diff_format(settings: &UserSettings) -> Result<DiffFormat, config::Co
     let config = settings.config();
     if let Some(args) = config.get("ui.diff.tool").optional()? {
         // External "tool" overrides the internal "format" option.
-        let tool = merge_tools::get_tool_config_from_args(settings, &args)?
-            .unwrap_or_else(|| MergeTool::External(ExternalMergeTool::with_diff_args(&args)));
+        let tool = if let CommandNameAndArgs::String(name) = &args {
+            merge_tools::get_tool_config(settings, name)?
+        } else {
+            None
+        }
+        .unwrap_or_else(|| MergeTool::External(ExternalMergeTool::with_diff_args(&args)));
         match tool {
             MergeTool::Builtin => {}
             MergeTool::External(tool) => {
diff --git a/cli/src/merge_tools/mod.rs b/cli/src/merge_tools/mod.rs
index a7681c947..b45b787ae 100644
--- a/cli/src/merge_tools/mod.rs
+++ b/cli/src/merge_tools/mod.rs
@@ -210,25 +210,17 @@ pub fn get_tool_config(
     }
 }
 
-/// Loads merge tool options from `[merge-tools.<name>]` if `args` is of
-/// unstructured string type.
-pub fn get_tool_config_from_args(
-    settings: &UserSettings,
-    args: &CommandNameAndArgs,
-) -> Result<Option<MergeTool>, ConfigError> {
-    match args {
-        CommandNameAndArgs::String(name) => get_tool_config(settings, name),
-        CommandNameAndArgs::Vec(_) | CommandNameAndArgs::Structured { .. } => Ok(None),
-    }
-}
-
 fn get_diff_editor_from_settings(
     ui: &Ui,
     settings: &UserSettings,
 ) -> Result<MergeTool, ExternalToolError> {
     let args = editor_args_from_settings(ui, settings, "ui.diff-editor")?;
-    let editor = get_tool_config_from_args(settings, &args)?
-        .unwrap_or_else(|| MergeTool::External(ExternalMergeTool::with_edit_args(&args)));
+    let editor = if let CommandNameAndArgs::String(name) = &args {
+        get_tool_config(settings, name)?
+    } else {
+        None
+    }
+    .unwrap_or_else(|| MergeTool::External(ExternalMergeTool::with_edit_args(&args)));
     Ok(editor)
 }
 
@@ -237,8 +229,12 @@ fn get_merge_tool_from_settings(
     settings: &UserSettings,
 ) -> Result<MergeTool, ExternalToolError> {
     let args = editor_args_from_settings(ui, settings, "ui.merge-editor")?;
-    let mergetool = get_tool_config_from_args(settings, &args)?
-        .unwrap_or_else(|| MergeTool::External(ExternalMergeTool::with_merge_args(&args)));
+    let mergetool = if let CommandNameAndArgs::String(name) = &args {
+        get_tool_config(settings, name)?
+    } else {
+        None
+    }
+    .unwrap_or_else(|| MergeTool::External(ExternalMergeTool::with_merge_args(&args)));
     match mergetool {
         MergeTool::External(mergetool) if mergetool.merge_args.is_empty() => {
             Err(ExternalToolError::MergeArgsNotConfigured {