What If You Don’t Need MCP at All?

Source: https://mariozechner.at/posts/2025-12-12-what-if-you-dont-need-mcp-at-all/ Author: mariozechner.at (Mario Zechner) Date: 2025-12-12

Summary

Mario Zechner (same author as the slowing down piece the same day) argues that the Model Context Protocol (MCP) is over-engineered for most use cases. Simple function calling often suffices.

Key Claims

  • MCP (Model Context Protocol): Anthropic’s standard for giving AI assistants access to external data sources and tools.
  • The MCP premise: standardize how tools connect to AI assistants so tools can be reused across different AI systems.
  • Zechner’s critique: for most individual developers, custom function calling is simpler and just as effective.
  • When MCP makes sense: when you’re building tools that many different AI systems should use.
  • When it’s overkill: when you’re building a single AI application with a fixed set of tools.
  • The abstraction cost: MCP adds indirection and complexity. Only worthwhile if the reusability benefit is realized.

Concepts