$tools */ public function __construct(public readonly array $tools = [], public readonly ?string $strategy = null) { if ($strategy !== null && ! in_array($strategy, ['regex', 'bm25'], true)) { throw new InvalidArgumentException( "Invalid tool search strategy [{$strategy}]. Supported strategies: regex, bm25." ); } } /** * Get a copy of the tool search with the given deferred tools. * * @param array $tools */ public function withTools(array $tools): self { $clone = new self($tools, $this->strategy); $clone->providerOptions = $this->providerOptions; return $clone; } /** * Count the given tools for step budgeting, expanding each ToolSearch into its deferred tools. * * @param array $tools */ public static function budget(array $tools): int { return array_sum(array_map( fn ($tool) => $tool instanceof self ? count($tool->tools) : 1, $tools, )); } }