import type { AgentModelConfig, Config } from '../../config/schema.js';
export type ToolModelConfig = {
    primary?: string;
    fallbacks?: string[];
};
export declare function hasToolModelConfig(model: ToolModelConfig | undefined): boolean;
export declare function resolveDefaultModelRef(cfg?: Config): {
    provider: string;
    model: string;
};
export declare function coerceToolModelConfig(model?: AgentModelConfig): ToolModelConfig;
export declare function buildToolModelConfigFromCandidates(params: {
    explicit: ToolModelConfig;
    candidates: Array<string | null | undefined>;
}): ToolModelConfig | null;
/**
 * Effective image understanding model: explicit `agents.defaults.imageModel`, else inferred from configured providers.
 */
export declare function resolveImageModelConfigForTool(params: {
    cfg?: Config;
}): ToolModelConfig | null;
