Enum ToolError 

pub enum ToolError {
    InvalidParams(String),
    PolicyRejected(String),
    SizeLimitExceeded(String),
    Internal(String),
}

Errors returned from ToolHandler::call.

Each variant maps to a JSON-RPC -32000 application-error response. The serve loop converts these to the wire format.

Variants

InvalidParams(String)

The caller supplied parameters that do not match the tool schema.

PolicyRejected(String)

A policy gate returned Reject, Quarantine, or BreakGlass.

Per ADR 0045 §3, a BreakGlass composed outcome is treated as Reject at the MCP boundary. No write occurs when this variant is returned.

SizeLimitExceeded(String)

The incoming payload exceeds the server-side size limit (RT-5).

Internal(String)

An unexpected internal error that is not one of the above categories.

Implementations

impl ToolError

pub const fn kind(&self) -> &'static str

Stable machine-readable refusal class for JSON-RPC error.data.

pub fn resolution_data(&self) -> Value

Structured operator-facing remediation data for MCP clients.

The human message remains short in error.message; this envelope gives clients enough deterministic shape to render a useful “what now?” panel without weakening the refusal or inventing an override path.

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.