Domain 2: Tool Design & MCP Integration (18%)
5 lessons, each ending with a practice scenario (Pro)
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- ✓2.1 — Tool Interface DesignTool descriptions are the primary mechanism LLMs use for tool selection. Minimal descriptions leave the model no way to tell overlapping tools apart.Scenario: Pro
- ✓2.2 — Structured Error ResponsesA structured error response tells the agent the error's category, whether a retry can work, and how to recover. The MCP protocol provides the isError flag.Scenario: Pro
- ✓2.3 — Tool Distribution & Tool ChoiceTool distribution is the choice of which agent in a multi-agent system holds which tools. The number of tools an agent holds directly affects selection reliability.Scenario: Pro
- ✓2.4 — MCP Server IntegrationAn MCP server extends Claude by connecting it to an external system (database, API, development tool, issue tracker).Scenario: Pro
- ✓2.5 — Built-in ToolsClaude Code provides six built-in tools: Read, Write, Edit, Bash, Grep, Glob. Grep vs Glob: Grep, Glob; Grep finds what is inside files. Glob finds files by their names.Scenario: Pro
Domain recapQuick overview of all lessons
5 Task Statements / Lessons
2.1 Tool Interface Design
JSON Schema best practices for input_schema: clear names, descriptions that tell the model when to call the tool, required vs optional parameters, enums for constrained values.
2.2 Structured Error Responses
Return structured, model-readable errors so Claude can recover or ask clarifying questions instead of hallucinating success.
2.3 Tool Distribution & Tool Choice
How many tools to expose at once, progressive disclosure of tools, tool routing / selection strategies when the set is large.
2.4 MCP Server Integration
Model Context Protocol: writing MCP servers, exposing resources/tools/prompts, client-side integration patterns, authentication and scoping.
2.5 Built-in Tools
Claude’s built-in tools (computer use, code execution, web search, etc.) — when to prefer them over custom tools and how they interact with the agentic loop.
Exam mindset: Prefer the simplest tool surface that solves the problem. Overly complex schemas and monolithic tool sets are common distractors.
Domain 3: Claude Code configuration & workflows →