feat(config): Add style.error override for tool error responses

crates/jp_cli/src/cmd/conversation/print.rs

@@ -1,5 +1,7 @@
 use jp_config::{
-    conversation::tool::style::{self, DisplayStyleConfig, InlineResults, ParametersStyle},
+    conversation::tool::style::{
+        self, DisplayStyleConfig, ErrorStyleConfig, InlineResults, ParametersStyle,
+    },
     style::{reasoning::ReasoningDisplayConfig, typewriter::DelayDuration},
 };
 use jp_workspace::ConversationHandle;
@@ -16,6 +18,10 @@ const BRIEF_TOOL_STYLE: DisplayStyleConfig = DisplayStyleConfig {
     parameters: ParametersStyle::Off,
     inline_results: InlineResults::Off,
     results_file_link: style::LinkStyle::Off,
+    error: ErrorStyleConfig {
+        inline_results: None,
+        results_file_link: None,
+    },
 };
 
 /// Chat-mode tool display style: tool calls are fully hidden.
@@ -24,6 +30,10 @@ const CHAT_TOOL_STYLE: DisplayStyleConfig = DisplayStyleConfig {
     parameters: ParametersStyle::Off,
     inline_results: InlineResults::Off,
     results_file_link: style::LinkStyle::Off,
+    error: ErrorStyleConfig {
+        inline_results: None,
+        results_file_link: None,
+    },
 };
 
 /// Full-mode tool display style: everything visible, nothing truncated.
@@ -32,6 +42,10 @@ const FULL_TOOL_STYLE: DisplayStyleConfig = DisplayStyleConfig {
     parameters: ParametersStyle::Json,
     inline_results: InlineResults::Full,
     results_file_link: style::LinkStyle::Full,
+    error: ErrorStyleConfig {
+        inline_results: None,
+        results_file_link: None,
+    },
 };
 
 #[derive(Debug, clap::Args)]

crates/jp_cli/src/cmd/query/tool/builtins.rs

@@ -2,7 +2,10 @@ use indexmap::IndexMap;
 use jp_config::conversation::tool::{
     Enable, PartialOneOrManyTypes, PartialToolConfig, PartialToolParameterConfig, RunMode,
     ToolSource,
-    style::{InlineResults, LinkStyle, ParametersStyle, PartialDisplayStyleConfig},
+    style::{
+        InlineResults, LinkStyle, ParametersStyle, PartialDisplayStyleConfig,
+        PartialErrorStyleConfig,
+    },
 };
 
 pub fn all() -> IndexMap<String, PartialToolConfig> {
@@ -34,6 +37,7 @@ pub fn describe_tools() -> PartialToolConfig {
             inline_results: Some(InlineResults::Off),
             results_file_link: Some(LinkStyle::Off),
             parameters: Some(ParametersStyle::Off),
+            error: PartialErrorStyleConfig::default(),
         }),
         ..Default::default()
     }

crates/jp_cli/src/cmd/query/tool/coordinator.rs

@@ -1038,13 +1038,14 @@ impl ToolCoordinator {
                         .get(&index)
                         .map(|t| t.tool_name.clone())
                         .unwrap_or_default();
+                    let is_error = response.result.is_err();
                     let (inline_results, results_file_link) = self
                         .tools_config
                         .get(&tool_name)
                         .map(|c| {
                             (
-                                c.style().inline_results.clone(),
-                                c.style().results_file_link.clone(),
+                                c.style().inline_results(is_error).clone(),
+                                c.style().results_file_link(is_error).clone(),
                             )
                         })
                         .unwrap_or_default();
@@ -1252,13 +1253,14 @@ impl ToolCoordinator {
     ) {
         match result {
             ExecutorResult::Completed(response) => {
+                let is_error = response.result.is_err();
                 let (inline_results, results_file_link) = self
                     .tools_config
                     .get(&tool.tool_name)
                     .map(|c| {
                         (
-                            c.style().inline_results.clone(),
-                            c.style().results_file_link.clone(),
+                            c.style().inline_results(is_error).clone(),
+                            c.style().results_file_link(is_error).clone(),
                         )
                     })
                     .unwrap_or_default();

crates/jp_cli/src/cmd/query/turn_loop_tests.rs

@@ -16,7 +16,7 @@ use jp_config::{
     conversation::tool::{
         CommandConfigOrString, PartialCommandConfigOrString, PartialToolConfig, QuestionConfig,
         QuestionTarget, RunMode, ToolConfig, ToolSource,
-        style::{DisplayStyleConfig, InlineResults, LinkStyle, ParametersStyle},
+        style::{DisplayStyleConfig, ErrorStyleConfig, InlineResults, LinkStyle, ParametersStyle},
     },
     model::id::{self, Name, PartialModelIdConfig, ProviderId},
 };
@@ -2634,6 +2634,10 @@ async fn test_parallel_tool_calls_rendered_atomically() {
             inline_results: InlineResults::Off,
             results_file_link: LinkStyle::Off,
             parameters: ParametersStyle::FunctionCall,
+            error: ErrorStyleConfig {
+                inline_results: None,
+                results_file_link: None,
+            },
         });
 
         // Configure tools with FunctionCall style for readable output.

crates/jp_cli/src/render/turn.rs

@@ -131,16 +131,15 @@ impl TurnRenderer {
                     let name = self.tool_names.get(&resp.id);
                     let default_style = &self.tools_config.defaults.style;
                     let tool_cfg = name.and_then(|n| self.tools_config.get(n));
-                    let style = tool_cfg
-                        .as_ref()
-                        .map_or(default_style, ToolConfigWithDefaults::style);
+                    let tool_style = tool_cfg.as_ref().map_or(default_style, |c| c.style());
+                    let is_error = resp.result.is_err();
+                    let hidden = tool_style.hidden;
+                    let inline_results = tool_style.inline_results(is_error);
+                    let results_file_link = tool_style.results_file_link(is_error);
 
-                    if !style.hidden {
-                        self.tool.render_result(
-                            resp,
-                            &style.inline_results,
-                            &style.results_file_link,
-                        );
+                    if !hidden {
+                        self.tool
+                            .render_result(resp, inline_results, results_file_link);
                     }
                 }
 

crates/jp_config/src/conversation/tool.rs

@@ -334,7 +334,8 @@ pub struct ToolConfig {
 
     /// How to display the results of the tool in the terminal.
     ///
-    /// Overrides the global default.
+    /// Overrides the global default. The error overlay lives at
+    /// `style.error.*` (see [`DisplayStyleConfig::error`]).
     #[setting(nested)]
     pub style: Option<DisplayStyleConfig>,
 

crates/jp_config/src/conversation/tool/style.rs

@@ -1,4 +1,23 @@
 //! Display style configuration for tools.
+//!
+//! User-facing shape under `[style]`:
+//!
+//! ```toml
+//! [tools.my_tool.style]
+//! hidden = false           # applies to both request and response
+//! parameters = "json"      # how arguments are rendered on the call
+//! inline_results = "full"  # how successful results are rendered
+//! results_file_link = "osc8"
+//!
+//! [tools.my_tool.style.error]
+//! inline_results = "full"  # overrides on top of `style` for failed results
+//! ```
+//!
+//! [`ErrorStyleConfig`] (`error`) is a per-field overlay applied when the
+//! tool result is `Err`. Unset overlay fields take their value from the
+//! matching top-level field. The overlay is typed separately so the
+//! error path can grow its own fields (severity styling, alternate
+//! sinks, etc.) independently of the success path.
 
 use std::{fmt, num::ParseIntError, str::FromStr};
 
@@ -11,10 +30,12 @@ use crate::{
     conversation::tool::CommandConfigOrString,
     delta::{PartialConfigDelta, delta_opt},
     fill::FillDefaults,
-    partial::{ToPartial, partial_opt},
+    partial::{ToPartial, partial_opt, partial_opts},
 };
 
 /// Display style configuration.
+///
+/// See the [module-level docs](self) for the user-facing TOML shape.
 #[derive(Debug, Clone, PartialEq, Config)]
 #[config(rename_all = "snake_case")]
 pub struct DisplayStyleConfig {
@@ -49,16 +70,61 @@ pub struct DisplayStyleConfig {
     /// - `<command>`: Use a custom command to format the parameters.
     #[setting(default)]
     pub parameters: ParametersStyle,
+
+    /// Per-field overrides applied when the tool result is `Err`. Unset
+    /// overlay fields take their value from the matching top-level field.
+    ///
+    /// Sub-fields appear under `[style.error]` in TOML.
+    #[setting(nested)]
+    pub error: ErrorStyleConfig,
+}
+
+impl DisplayStyleConfig {
+    /// Return the effective [`InlineResults`] for a tool response.
+    ///
+    /// For error responses, the `style.error.inline_results` overlay is
+    /// applied on top of `style.inline_results`. Successful responses
+    /// read `style.inline_results` directly.
+    #[must_use]
+    pub fn inline_results(&self, is_error: bool) -> &InlineResults {
+        if is_error {
+            self.error
+                .inline_results
+                .as_ref()
+                .unwrap_or(&self.inline_results)
+        } else {
+            &self.inline_results
+        }
+    }
+
+    /// Return the effective [`LinkStyle`] for the results-file link of a
+    /// tool response.
+    ///
+    /// For error responses, the `style.error.results_file_link` overlay
+    /// is applied on top of `style.results_file_link`. Successful
+    /// responses read `style.results_file_link` directly.
+    #[must_use]
+    pub fn results_file_link(&self, is_error: bool) -> &LinkStyle {
+        if is_error {
+            self.error
+                .results_file_link
+                .as_ref()
+                .unwrap_or(&self.results_file_link)
+        } else {
+            &self.results_file_link
+        }
+    }
 }
 
 impl AssignKeyValue for PartialDisplayStyleConfig {
-    fn assign(&mut self, kv: KvAssignment) -> AssignResult {
+    fn assign(&mut self, mut kv: KvAssignment) -> AssignResult {
         match kv.key_string().as_str() {
             "" => kv.try_merge_object(self)?,
             "hidden" => self.hidden = kv.try_some_bool()?,
             "inline_results" => self.inline_results = kv.try_some_from_str()?,
             "results_file_link" => self.results_file_link = kv.try_some_from_str()?,
             "parameters" => self.parameters = kv.try_some_from_str()?,
+            _ if kv.p("error") => self.error.assign(kv)?,
             _ => return missing_key(&kv),
         }
 
@@ -73,6 +139,7 @@ impl PartialConfigDelta for PartialDisplayStyleConfig {
             inline_results: delta_opt(self.inline_results.as_ref(), next.inline_results),
             results_file_link: delta_opt(self.results_file_link.as_ref(), next.results_file_link),
             parameters: delta_opt(self.parameters.as_ref(), next.parameters),
+            error: self.error.delta(next.error),
         }
     }
 }
@@ -84,6 +151,7 @@ impl FillDefaults for PartialDisplayStyleConfig {
             inline_results: self.inline_results.or(defaults.inline_results),
             results_file_link: self.results_file_link.or(defaults.results_file_link),
             parameters: self.parameters.or(defaults.parameters),
+            error: self.error.fill_from(defaults.error),
         }
     }
 }
@@ -97,6 +165,66 @@ impl ToPartial for DisplayStyleConfig {
             inline_results: partial_opt(&self.inline_results, defaults.inline_results),
             results_file_link: partial_opt(&self.results_file_link, defaults.results_file_link),
             parameters: partial_opt(&self.parameters, defaults.parameters),
+            error: self.error.to_partial(),
+        }
+    }
+}
+
+/// Per-field overrides for rendering failed tool call responses.
+///
+/// Each field is optional. Callers resolve an unset field by reading the
+/// matching field from the parent [`DisplayStyleConfig`].
+#[derive(Debug, Clone, PartialEq, Default, Config)]
+#[config(rename_all = "snake_case")]
+pub struct ErrorStyleConfig {
+    /// Override for [`DisplayStyleConfig::inline_results`].
+    pub inline_results: Option<InlineResults>,
+
+    /// Override for [`DisplayStyleConfig::results_file_link`].
+    pub results_file_link: Option<LinkStyle>,
+}
+
+impl AssignKeyValue for PartialErrorStyleConfig {
+    fn assign(&mut self, kv: KvAssignment) -> AssignResult {
+        match kv.key_string().as_str() {
+            "" => kv.try_merge_object(self)?,
+            "inline_results" => self.inline_results = kv.try_some_from_str()?,
+            "results_file_link" => self.results_file_link = kv.try_some_from_str()?,
+            _ => return missing_key(&kv),
+        }
+
+        Ok(())
+    }
+}
+
+impl PartialConfigDelta for PartialErrorStyleConfig {
+    fn delta(&self, next: Self) -> Self {
+        Self {
+            inline_results: delta_opt(self.inline_results.as_ref(), next.inline_results),
+            results_file_link: delta_opt(self.results_file_link.as_ref(), next.results_file_link),
+        }
+    }
+}
+
+impl FillDefaults for PartialErrorStyleConfig {
+    fn fill_from(self, defaults: Self) -> Self {
+        Self {
+            inline_results: self.inline_results.or(defaults.inline_results),
+            results_file_link: self.results_file_link.or(defaults.results_file_link),
+        }
+    }
+}
+
+impl ToPartial for ErrorStyleConfig {
+    fn to_partial(&self) -> Self::Partial {
+        let defaults = Self::Partial::default();
+
+        Self::Partial {
+            inline_results: partial_opts(self.inline_results.as_ref(), defaults.inline_results),
+            results_file_link: partial_opts(
+                self.results_file_link.as_ref(),
+                defaults.results_file_link,
+            ),
         }
     }
 }