Struct ToolError 

pub struct ToolError { /* private fields */ }

An error raised by a tool, resource or prompt handler.

• ToolError::user errors are shown to the client: as an isError tool result (so the model can correct itself), or as a -32602 error for resources and prompts. Use them for invalid input or business-rule violations.
• Any other error (? on a std::error::Error) is logged with full detail on the server, and the client receives a generic message.

Implementations

impl ToolError

pub fn user(message: impl Into<Cow<'static, str>>) -> Self

An error whose message is shown to the model.

pub fn not_found() -> Self

The requested item does not exist. From a resource handler, this is the specification’s resource-not-found error (-32602 with data.uri); from a tool, an isError result.

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

Invalid input, with a client-safe explanation (shown to the client).

pub fn protocol(error: McpError) -> Self

A protocol-level (JSON-RPC) error instead of a tool result. Use it for conditions the specification defines as protocol errors, such as a missing client capability.

pub fn missing_client_capability(required: &ClientCapabilities) -> Self

The request needs client capabilities the client did not declare: a -32021 JSON-RPC error (HTTP 400) listing them, as the specification requires. See Ctx::client_capabilities.

pub fn internal( error: impl Into<Box<dyn Error + Send + Sync + 'static>>, ) -> Self

An internal error: logged on the server, hidden from the client.

pub fn invalid_arguments(error: &Error) -> Self

The arguments did not match the tool’s input schema. The message comes from the deserializer and only describes the client’s own input.

Trait Implementations

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 IntoToolError for ToolError

fn into_tool_error(self) -> ToolError

Performs the conversion.