Struct ToolError 

pub struct ToolError {
    pub message: String,
    /* private fields */
}

An error returned from a tool execution. The error message is sent back to the model as the tool’s error response. Structured metadata can be attached for hooks and logging — it is not sent to the model.

Implements From<String> and From<&str> for ergonomic construction.

Example

use llm_tool::ToolError;
use serde::Serialize;

let err: ToolError = "something went wrong".into();
assert_eq!(err.to_string(), "something went wrong");

let err = ToolError::new(format!("failed to read {}", "file.txt"));
assert!(err.to_string().contains("file.txt"));

// Structured metadata from a typed struct (preferred)
#[derive(Serialize)]
struct HttpErrorMeta {
    status_code: u16,
    url: String,
}

let err = ToolError::new("HTTP request failed")
    .with_metadata(&HttpErrorMeta {
        status_code: 503,
        url: "https://example.com".into(),
    })
    .unwrap();
assert_eq!(err.metadata()["status_code"], 503);

// Single ad-hoc entry
let err = ToolError::new("timeout").with_meta("retry_after_secs", serde_json::json!(30));
assert_eq!(err.metadata()["retry_after_secs"], 30);

Fields

message: String

Human-readable error message sent to the model.

Implementations

impl ToolError

pub fn new(message: impl Into<String>) -> Self

Create a new tool error with no metadata.

pub fn with_meta(self, key: impl Into<String>, value: Value) -> Self

Attach a single metadata key-value pair. Chainable.

For attaching multiple fields at once, prefer with_metadata with a typed struct.

pub fn with_metadata<T: Serialize>(self, value: &T) -> Result<Self, Self>

Attach structured metadata from a serializable value.

The value is serialized to a JSON object and its fields are merged into the metadata map. See ToolOutput::with_metadata for details.

Errors

Returns Err(self) if value doesn’t serialize to a JSON object.

pub fn metadata(&self) -> &HashMap<String, Value>

The structured metadata map.

Trait Implementations

impl Clone for ToolError

fn clone(&self) -> ToolError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ToolError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for ToolError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for ToolError

impl Error for ToolError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<&str> for ToolError

fn from(message: &str) -> Self

Converts to this type from the input type.

impl From<Box<dyn Error + Send + Sync>> for ToolError

fn from(e: Box<dyn Error + Send + Sync>) -> Self

Converts to this type from the input type.

impl From<Error> for ToolError

fn from(e: Error) -> Self

Converts to this type from the input type.

impl From<Error> for ToolError

fn from(e: Error) -> Self

Converts to this type from the input type.

impl From<Infallible> for ToolError

fn from(never: Infallible) -> Self

Converts to this type from the input type.

impl From<String> for ToolError

fn from(message: String) -> Self

Converts to this type from the input type.

impl PartialEq for ToolError

fn eq(&self, other: &ToolError) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ToolError