Tools¶

Tools let the agent take actions. The LLM decides which tool to call and with what arguments.

Registering Tools¶

Pass tools to the Tools collection:

use Cognesy\Agents\Core\Collections\Tools;
use Cognesy\Agents\Core\Tools\MockTool;

$calculator = MockTool::returning('calculator', 'Performs math', '42');
$tools = new Tools($calculator);

Using FunctionTool¶

Wrap any callable as a tool. Parameter schema is auto-generated from the function signature:

use Cognesy\Agents\Core\Tools\FunctionTool;

$tool = FunctionTool::fromCallable(
    function (string $city): string {
        return "Weather in {$city}: 72F, sunny";
    }
);

$tools = new Tools($tool);

Agent with Tools¶

use Cognesy\Agents\Core\AgentLoop;
use Cognesy\Agents\Core\Collections\Tools;
use Cognesy\Agents\Core\Data\AgentState;

$loop = AgentLoop::default()->withTool($tool);

$state = AgentState::empty()->withUserMessage('What is the weather in Paris?');
$result = $loop->execute($state);
// LLM calls the weather tool, gets result, then responds

How It Works¶

LLM sees tool schemas and decides to call a tool
ToolExecutor runs the tool with provided arguments
Tool results are formatted as messages and fed back to the LLM
LLM uses the results to formulate a final response
Loop continues until LLM responds without tool calls