QABattle

MCP & Protocol Testing / Quiz

Context: The Injected Superpower

ctx by type hint: client logging, progress reporting, resource reads, and LLM sampling from inside a tool, plus the stdout trap that corrupts stdio.

Difficulty
Medium
Format
Quiz
Points
150
Estimate
9 min

// MISSION BRIEF

Your Mission

FastMCP tools can do more than compute: through the injected Context they log to the client, stream progress, read the server's own resources, and even borrow the client's LLM. The injection mechanism itself is a favorite interview question, and the stdout trap has broken more stdio servers than any protocol bug.

Six questions. Speed bonus active.

// FIRST CONTACT

Battle teaser

How does a FastMCP tool receive the Context object?

  1. ACall FastMCP.get_context() as a global anywhere
  2. BClients pass context as the first JSON argument
  3. CName any parameter exactly 'ctx'; the name triggers injection
  4. DDeclare a parameter type-hinted as Context; injection matches the TYPE hint (the parameter name is irrelevant), and the parameter is excluded from the tool's public schema
Answers, scoring, hints, and the full battle stay sealed.

// SKILL TAGS

fastmcpcontextsamplingmcp