CCDV-F questions and answers — Domain 5: Tools and MCPs

6 practice questions on Tools and MCPs, the domain weighted at 10.6% of the CCDV-F exam. Every answer explains why the distractors fail — that is the part that transfers to questions you have not seen before.

Question 1

Your search_orders tool keeps receiving malformed date arguments. What is the most reliable fix?

1. Describe the date format in the system prompt
2. Tighten the schema: format guidance in the parameter description, additionalProperties: false, and strict: true
3. Parse loosely and guess the intended date
4. Use a more capable model

Answer: B. The schema is the contract the arguments are generated against, and strict makes conformance enforced rather than requested. System-prompt notes about one parameter get lost among many tools, and guessing at malformed input creates silent wrong answers.

Question 2

Which MCP primitives are exposed by servers?

1. Sampling, elicitation and logging
2. Tools, resources and prompts
3. Tools, sampling and roots
4. Resources, transports and sessions

Answer: B. Servers expose tools (actions), resources (context data) and prompts (reusable templates). Sampling, elicitation and logging are the client-side primitives — the ways a server can ask the host to run a completion, ask the user something, or emit logs.

Question 3

An MCP server runs as a local subprocess beside a single client. Which transport, and why?

1. Streamable HTTP, for OAuth support
2. stdio, because it is direct process communication with no network overhead
3. WebSocket, for bidirectionality
4. SSE, as the modern default

Answer: B. stdio is designed for a local process serving one client. Streamable HTTP is for remote servers serving many clients with standard HTTP authentication. SSE as a standalone transport is deprecated.

Question 4

A stdio MCP server connects, then immediately fails with protocol errors. The code includes print("server starting"). What is wrong?

1. The server must log before initialisation completes
2. stdout carries the JSON-RPC stream, and anything else written there corrupts it
3. print is too slow for a server loop
4. The message must be JSON-encoded

Answer: B. In a stdio transport, stdout is the protocol channel. print() in Python and console.log() in Node write there by default and break the stream in a way that presents as a connection fault. Log to stderr.

Question 5

You want a team to share an MCP server configuration through source control. Where does it go?

1. ~/.claude.json at user scope
2. .mcp.json at the project root, with ${VAR} expansion for credentials
3. .claude/settings.local.json
4. An environment variable per developer

Answer: B. Project scope writes to a committed .mcp.json. Environment expansion — ${VAR} and ${VAR:-default} — keeps secrets out of the committed file. Local and user scopes are personal to one machine.

Question 6

An agent has fifteen narrow tools and frequently selects the wrong one. What is the most likely improvement?

1. Add a tool that explains the other tools
2. Consolidate overlapping micro-tools into fewer high-level tools with descriptions that say when to use each
3. Register each tool twice under different names
4. Increase the temperature

Answer: B. Every tool costs context and adds a chance of mis-selection. Consolidation reduces both, and the description is the routing signal — it should say when to call the tool, not only what it does. Meta-tools and duplicate registrations enlarge the surface that caused the problem.

← Previous: Questions & answers — Domain 4  |  Next: Questions & answers — Domains 6–8 →