/** Thrown when a tool execution exceeds its configured timeout. */
export declare class ToolTimeoutError extends Error {
    readonly toolName: string;
    readonly timeoutMs: number;
    constructor(toolName: string, timeoutMs: number);
}
/**
 * Thrown by a tool's `execute` (or a guard wrapping it) when the call failed for a
 * reason the model can correct: a referent that does not exist ("Unknown unit '12B'"),
 * a value out of range, a missing precondition the user can supply. Distinct from a
 * fatal fault (network down, schema broken) in that the model should see the message
 * and retry — not be told "something went wrong on my side".
 *
 * On the model path it is returned to the model as a tool result (the model self-corrects).
 * On the flow path it is the signal to re-collect the offending input instead of
 * degrading the flow — see `runFlow`. Detected by type (`isRecoverableToolError`), never
 * by string-matching the message.
 */
export declare class RecoverableToolError extends Error {
    /**
     * Author-written copy shown to the USER, verbatim, when a flow re-asks after this
     * error. `message` is for the model; a business rejection ("that unit already has
     * an open work order") is useless to the person unless someone tells them, and the
     * collect node's `ask` is deterministic precisely so the model cannot rephrase it.
     */
    readonly userMessage?: string;
    constructor(message: string, options?: {
        userMessage?: string;
    });
}
/** Thrown when a human denies a tool call that requires approval. */
export declare class ToolApprovalDeniedError extends Error {
    readonly toolName: string;
    readonly by?: string;
    /** Why, when a policy refused. Human denials carry no reason — the human just said no. */
    readonly reason?: string;
    constructor(toolName: string, by?: string, reason?: string);
}