QABattle

MCP & Protocol Testing / Scenario

Breaking Change Detector

An MCP server bumped a version and 'tidied' a tool. Downstream agents fell over. Classify each change and design the gate that stops the next one.

Difficulty
Hard
Format
Scenario
Points
200
Estimate
16 min

// MISSION BRIEF

Your Mission

A platform team ships an MCP server used by many agent teams. This release changed the protocol version and refactored the export_report tool. Some agents broke; the team is not sure why.

You have the version negotiation change, the tool schema diff, and the fallout. Separate the breaking changes from the safe ones, and specify the automated gate that would have caught the breaks pre-release.

// FIRST CONTACT

Battle teaser

First artifact

export_report tool: before vs after

Which schema changes are BREAKING for existing callers? (Select all that apply.)

  1. ARenaming 'email' to 'recipient'
  2. BMaking 'format' newly required
  3. CRemoving 'json' from the format enum (narrowing an enum)
  4. DAdding the optional 'watermark' boolean
Answers, scoring, hints, and the full battle stay sealed.

// SKILL TAGS

mcpversioningbreaking-changescontract-testingci-cd