MCP Code Execution Pattern

Expert knowledge for designing agent systems that generate and execute code to interact with MCP servers, instead of calling tools directly.

When to Use This Pattern

Use code execution when...	Use direct tool calls when...
Connecting to 10+ MCP servers or 50+ tools	Few servers with handful of tools
Intermediate results are large (>10K tokens)	Results are small and all needed by the model
Workflows need loops, retries, or conditionals	Linear sequences of 2-3 tool calls
PII must not reach the model context	No sensitive data in tool responses
Tasks benefit from state persistence across runs	Stateless, one-shot operations
You want agents to accumulate reusable skills	Fixed, predefined workflows