pub fn tool_fail(
message: impl Into<String>,
code: Option<String>,
hint: Option<String>,
) -> ErrorExpand description
Build a coded tool-failure Error (parity with Node new ToolError(message, {code, hint})).
Throwing this from a safe_tool body produces {success:false, code, error, hint?}; thrown
from a classic tool() body, the catch site formats it via format_tool_error as JSON.