How to build reliable tool calls for AI agents integrating with external APIs

Integrating Large Language Model (LLM) AI agents with external APIs presents challenges due to the probabilistic nature of LLMs and the deterministic requirements of APIs. Direct connections often lead to reliability issues, as LLMs can produce varied outputs, leading to incorrect tool usage, data integrity problems, and increased costs. To enhance reliability, it's recommended to transfer deterministic logic from the LLM into the tool's execution code, reducing the agent's decision-making burden. Custom tools tailored to specific user intents should be designed, minimizing the risk of failure by handling business logic within the code itself. Additionally, optimizing tool output, minimizing non-deterministic parameters, centralizing request construction, and implementing robust validation and error handling can further stabilize integrations. Observability is crucial, allowing for monitoring and analysis of tool call success and failure rates. Platforms like Nango facilitate the creation of reliable tool calls by providing custom tool-building capabilities, handling API authentication, and offering observability features, which help streamline and secure API integrations for AI agents.