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CCAR-FAcademy

Domain 2 · 18% of the exam

Tool Design & MCP Integration

Domain 2 measures how well you design the surface an agent actually reasons over: the tools. It tests whether you can write tool descriptions precise enough to route reliably, return structured errors an agent can recover from, scope tool sets per agent and control invocation with tool_choice, wire MCP servers into Claude Code and Agent SDK workflows at the right scope, and pick the right one of the six built-in tools the guide names (Read, Write, Edit, Bash, Grep, Glob) for a given job. At 18% of the exam it is the second-smallest domain, but it is a primary domain for three of the six scenarios — the Customer Support Resolution Agent, the Multi-Agent Research System, and Developer Productivity with Claude.
5 statements 15 examples 8 diagrams ~12 min
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Choose a task statement

Each statement is a focused page. Your progress and quiz links still connect through the domain.

  1. 2.1 1 of 5

    Design effective tool interfaces with clear descriptions and boundaries

    Tool descriptions are the primary mechanism the model uses to select tools — treat them as production routing logic, not documentation. ~2 min · 3 examples · 1 diagrams
  2. 2.2 2 of 5

    Implement structured error responses for MCP tools

    MCP signals failure with the isError flag, but the flag alone carries no recovery information — the structured metadata you attach does. ~3 min · 3 examples · 2 diagrams
  3. 2.3 3 of 5

    Distribute tools appropriately across agents and configure tool choice

    Giving an agent 18 tools instead of 4–5 degrades selection reliability by increasing decision complexity on every turn. ~2 min · 3 examples · 1 diagrams
  4. 2.4 4 of 5

    Integrate MCP servers into Claude Code and agent workflows

    Project-scoped .mcp.json is for shared team tooling; user-scoped ~/.claude.json is for personal or experimental servers. ~2 min · 3 examples · 2 diagrams
  5. 2.5 5 of 5

    Select and apply built-in tools (Read, Write, Edit, Bash, Grep, Glob) effectively

    Grep searches file contents for patterns; Glob matches file paths by name or extension pattern — content versus path is the dividing line. ~2 min · 3 examples · 2 diagrams
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