Enum ToolError 

pub enum ToolError<E: Display> {
    Connection {
        source: ConnectionError,
    },
    AccessDenied {
        message: String,
    },
    Tool(E),
}

The top-level error type returned by all MCP tools. Wraps errors common to every tool (connection pool failures, access control denials) and delegates to a tool-specific inner error for anything unique to the individual tool’s logic.

Variants

Connection

Failed to check out or configure a database connection.

Fields

source: ConnectionError

The underlying connection error.

AccessDenied

The SQL statement was rejected by the access control authorizer. The query was syntactically valid but the configured permissions forbid the requested operation.

Fields

message: String

A human-readable description of why the operation was denied.

Tool(E)

An error specific to the tool’s own logic, forwarded from the tool’s dedicated error type.

Trait Implementations

impl<E: Debug + Display> Debug for ToolError<E>

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

Formats the value using the given formatter.

impl<E> Display for ToolError<E>

where E: Display + Display,

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

Formats the value using the given formatter.

impl<E: Display> Error for ToolError<E>

where Self: Debug + Display,

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<E: Display> IntoContents for ToolError<E>

Converts the error into MCP content by rendering the display string as text. This covers both the shared variants and the tool-specific inner error.

fn into_contents(self) -> Vec<Content>