MCP Dev Summit Mumbai 2026

MCP servers introduced a new kind of client: one driven by an LLM. Unlike traditional clients, this one is non-deterministic. It can call tools in unexpected sequences, with unpredictable inputs.

We can’t reliably test how an LLM will call our tools. This makes the MCP server the only component under our control and the one that must be tested rigorously. A well-designed server is a well-tested server.

While reviewing several popular MCP servers, I found that “works correctly” often means testing happy paths and checking that tool descriptions exist.

This talk introduces a practical testing model for MCP servers. Attendees will learn how to treat tool descriptions as functional contracts in their tests, how to design tests that cover real-world and deliberate out-of-order tool call sequences, essentially what an LLM would attempt, and how to validate error channels so that, when things go wrong, the server returns errors that are actually useful for an LLM to recover or respond appropriately. These are practical techniques that can be applied immediately.

The goal is to establish a testing mental model that can keep up with the fast-moving MCP ecosystem.