My MCP server was confidently lying: 3 rounds of pre-launch testing caught silent data loss

emahmoudnabil · reddit · 2026-08-25

The author maintains an MCP server providing compiler-accurate graphs of .NET codebases. Three rounds of pre-launch testing on real codebases caught critical bugs missed by 470+ tests: 1. False ambiguity in route matching; 2. Silent data drops on Blazor/Turborepo samples despite success messages; 3. Position collisions in chained calls. The key lesson: for MCP servers, silent errors are worse than crashes because agents trust the output. The author implemented invariants: count-equals-persisted and no-silent-categories.

Original post →

More from coding & agent

coding & agent channel →