CCAR-F Practice Test 4 — 25 Questions

Question 1

While working in a repository, an architect wants Claude Code to explain the purpose of a specific function in a large source file without altering any code or generating new files. Which mode should be used for this task?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Plan mode, because it prevents edits and focuses on producing an explanation or approach. Claude Code separates exploration from execution. Plan mode is the read-only posture intended for understanding code, answering questions, and outlining approaches; it will not modify files. When the goal is purely explanatory, choosing plan mode enforces the no-change requirement structurally instead of relying on the model's discretion.

Answer

Auto-accept edits mode, because approvals are bypassed and analysis proceeds faster

Answer

A new session started with the --dangerously-skip-permissions flag

Answer

Default edit mode, because Claude Code will simply describe the function without touching files

Question 2

A developer working in a monorepo wants Claude Code to follow the team's TypeScript conventions only when editing files under the `packages/api` directory, while letting other directories use different conventions. What is the most appropriate way to configure this in Claude Code?

Accepted Answer

Create a `CLAUDE.md` file inside `packages/api` containing the TypeScript conventions so Claude Code applies those instructions when working in that directory.. Claude Code discovers `CLAUDE.md` memory files by walking from the current directory up the tree, so a file placed inside `packages/api` is loaded exactly when the session operates there. This gives the API package its own TypeScript conventions while leaving sibling packages and the repository root untouched, matching the requirement for directory-scoped guidance.

Answer

Add the TypeScript conventions to the user-level `~/.claude/CLAUDE.md` file so they apply globally to every project the developer opens.

Answer

Set the `CLAUDE_CODE_MODEL` environment variable to a model fine-tuned on the API package's conventions before starting each session.

Answer

Add a `settings.json` entry with a `scope` field set to `packages/api` under the project's `.claude` directory to bind conventions to that path.

Question 3

An architect is building an MCP server that exposes a `read_file` tool. The tool's input schema currently defines `path` as a plain string. Security review requires that the tool never read outside a configured workspace root, and that the model receive a clear, machine-readable error when it attempts to do so. Which change to the tool design best satisfies this requirement?

Accepted Answer

Have the server resolve the requested path against the workspace root, reject traversal outside it, and return a structured error object.. The secure pattern is server-side enforcement plus a structured error. The MCP server should resolve the incoming path, confirm it stays within the workspace root, and return a typed error payload when it does not. That keeps the security boundary out of the model's control while still giving the model enough information to recover gracefully on the next turn.

Answer

Add a `root` parameter to the schema so the model can specify the allowed workspace root on each call.

Answer

Keep `path` as a string but document in the tool description that paths must stay inside the workspace root.

Answer

Constrain `path` in the JSON Schema with an `enum` of known filenames and reject any other value.

Question 4

You are building a customer-support agent with the Anthropic Messages API. The agent must call a `get_order_status` tool, and the result is required before it can decide whether to issue a refund. The tool sometimes takes several seconds to respond. Which approach best ensures the agent does not prematurely finalize its answer before the tool result is available?

Accepted Answer

After receiving a `tool_use` block, execute the tool and send a `user` message containing a `tool_result` block with the matching `tool_use_id` before requesting the next completion.. Tool use in the Anthropic Messages API is a multi-turn exchange: the model emits a `tool_use` block, the application executes the function, and the application returns a `tool_result` block tied to the same `tool_use_id`. The model cannot finalize a refund decision until that result is in context, so completing the round trip before the next completion is what prevents premature answers.

Answer

Use `stop_sequences` to halt generation whenever the model emits a `tool_use` block.

Answer

Set `tool_choice` to `{"type": "any"}` so the model is forced to call a tool on every turn.

Answer

Increase `max_tokens` so the model has room to wait for the tool response within the same completion.

Question 5

A developer is building a classification pipeline that routes support tickets into one of eight categories. They want Claude to return a category label and a confidence score between 0 and 1. The output must be parseable by a JSON parser without post-processing. They plan to use the Anthropic Messages API. Which approach best ensures the output is directly parseable JSON with the required fields?

Accepted Answer

Describe the JSON schema in the system prompt, prefill the assistant turn with `{`, and validate the response with a JSON parser.. Describing the schema in the system prompt gives Claude the keys and types to emit, and prefilling the assistant turn with `{` forces the response to begin as a JSON object with no preamble or markdown fence. Validating with a JSON parser catches rare deviations. Together these produce directly parseable output, unlike free-text formats, stop-sequence tricks, or high-temperature sampling.

Answer

Set `temperature` to 1 and rely on the model's creativity to produce varied but valid JSON.

Answer

Ask Claude to return the category and confidence in a single sentence like 'Category: X, Confidence: 0.9'.

Answer

Use the `stop_sequences` parameter set to '}' so Claude stops as soon as it finishes the JSON object.

Question 6

A developer is building a Claude-powered assistant that must answer questions using only an internal knowledge base of product manuals. The team wants to reduce fabricated answers about features that do not exist. Which approach best supports that goal?

Accepted Answer

Instruct Claude to answer only from the provided manual excerpts and to say it does not know when the excerpts lack the answer.. Fabrication drops when Claude is constrained to supplied excerpts and given explicit permission to abstain. That combination sets a clear source of truth and removes the incentive to invent undocumented features. Temperature increases, whole-corpus dumping, and generic helpfulness instructions either raise variability or fail to bound the answer source, leaving the fabrication risk intact.

Answer

Add a system prompt line telling Claude to be as helpful and thorough as possible in every answer.

Answer

Prepend the entire knowledge base to every prompt so Claude always has all product manuals available.

Answer

Raise the temperature so Claude can generate more creative and comprehensive product descriptions.

Question 7

An architect is designing an MCP server that exposes a tool to query a customer relationship management (CRM) system. The CRM API enforces per-tenant rate limits and returns HTTP 429 with a Retry-After header when exceeded. The architect wants the tool to behave predictably under load without the model having to reason about throttling. Which approach should the architect implement?

Accepted Answer

Implement server-side retry with exponential backoff and jitter that honors the Retry-After header, and surface a structured success or failure result to the model.. Rate-limit handling is an integration concern that should be encapsulated in the MCP server so the model never has to reason about HTTP 429 responses or timing. Honoring Retry-After with exponential backoff and jitter prevents synchronized retries and respects the upstream contract. The model then receives a normalized result it can act on, keeping tool behavior predictable under load.

Answer

Cache every CRM response indefinitely and serve cached data whenever the API returns 429.

Answer

Return the raw HTTP 429 response body to the model and instruct it in the tool description to retry after a delay.

Answer

Configure the MCP client to automatically retry the tool call a fixed number of times without any server-side logic.

Question 8

An architect is designing an MCP server that exposes tools for a customer relationship management (CRM) system. The tools include 'get_customer', 'update_customer', and 'delete_customer'. The architect wants to ensure that tool invocations are properly authorized and audited. Which two design elements should be included in the MCP server implementation? (Choose two.)

Accepted Answer

Validate the caller's OAuth 2.0 access token on every tool invocation before executing the operation.. The two correct elements are validating the caller's OAuth 2.0 access token on every invocation and logging full tool inputs/outputs with authenticated user ID and timestamp. Together they enforce authorization at the server and provide an audit trail. Token validation ensures only authorized callers can execute tools, while logging enables traceability and detection of misuse.

Answer

Rely on the model's system prompt to instruct it to only call tools when the user is authorized.

Answer

Embed the caller's identity and permissions in the tool input schema as required parameters.

Answer

Store a static API key in the MCP server configuration and use it for all tool calls regardless of caller.

Question 9

You are architecting a customer-support assistant that uses Claude with a 200K-token context window. Each session accumulates roughly 40K tokens of chat history, and you also inject a 30K-token product manual on every turn. Latency has become unacceptable because the full payload is re-sent each call. Which change best reduces latency while preserving the assistant's knowledge of earlier turns?

Accepted Answer

Enable prompt caching on the stable prefix (manual plus prior turns) so repeated tokens are served from cache instead of being reprocessed on each call.. Prompt caching is the architectural lever for repeated large prefixes: the manual and accumulated history are stable across turns, so caching their processed state avoids re-encoding tens of thousands of tokens on every request. Caching preserves the full context the assistant needs, unlike truncation, and it targets input processing cost, unlike max_tokens or batching, which address output length or throughput rather than interactive latency.

Answer

Batch all user questions into a single nightly asynchronous request using the Message Batches API.

Answer

Raise the max_tokens parameter so Claude can emit a longer response and finish the answer in fewer round trips.

Answer

Switch to a smaller model with a shorter context window and truncate the manual to the first 8K tokens.

Question 10

A financial-reporting agent must extract figures from quarterly filings and populate a downstream ledger. Auditors require that every extracted number be traceable to its source. Which design most directly satisfies the traceability requirement?

Accepted Answer

Have the model output each figure together with the source document name and the exact quoted sentence containing it.. Traceability means each ledger figure can be traced back to specific source text. Emitting the document name and the exact quoted sentence with every extracted number creates that link at extraction time, so audit review is direct rather than reconstructive. Logging, larger context, and numeric normalization improve debugging, accuracy, or formatting but never bind a value to its origin.

Answer

Increase the model's context window so it can ingest the entire filing at once and reduce extraction errors.

Answer

Apply a post-processing regex pass to normalize all numeric formats before writing to the ledger.

Answer

Log the raw model request and response payloads to an immutable store for later inspection.

Question 11

A travel-booking agent built on the Claude Messages API handles multi-turn conversations. During a session, the agent calls a search_flights tool and receives results. On the next user turn the agent suddenly invents a flight that was never returned by any tool. The architect reviews the request payload and sees that the prior assistant turn containing the tool_use block and the following user turn containing the tool_result block were both sent back to the API. What is the most likely cause of the hallucinated flight?

Accepted Answer

The tool_result block was returned in a separate user message but its tool_use_id did not match the id of the preceding tool_use block.. Tool results must be bound to the exact tool_use id Claude emitted, otherwise the model treats the returned data as unattached context and fills gaps with invented content. Preserving the assistant tool_use turn and its matching user tool_result turn keeps the grounded data authoritative, so the fix is verifying id correspondence rather than discarding history or tuning token limits.

Answer

The search_flights tool schema declared its parameters as strings while the agent passed integers, so the API silently dropped the returned results.

Answer

The max_tokens value was too low, which truncated the tool_result content and forced the model to reconstruct the missing flight details.

Answer

The agent should have cleared the conversation history and resent only the latest user message so the model would not be confused by stale tool output.

Question 12

An architect is designing a Claude-based contract review tool. Because contract clauses are long and interdependent, the team plans to use extended thinking to improve reasoning quality. Which TWO practices should the architect follow to use this capability correctly? (Choose two.)

Accepted Answer

Allocate a thinking budget that scales with task complexity and leave sufficient max_tokens for the final answer.. Extended thinking requires sizing the thinking budget to task complexity while preserving room for the final answer, and it requires not recycling prior thinking blocks into later turns. Together these keep reasoning thorough, cost proportionate, and multi-turn dialogues clean. Exposing thinking traces, maxing budgets unconditionally, and returning only thinking output all misuse the capability.

Answer

Disable the final answer and return only the thinking output as the contract review result.

Answer

Set the thinking budget to the maximum on every request to guarantee the best possible clause analysis.

Answer

Expose the raw thinking blocks to end users so they can audit the model's reasoning trace.

Question 13

An architect is designing a prompt that asks Claude to analyze a contract and return a risk rating plus supporting clauses. The response must be machine-readable and include a confidence score. Which design most reliably produces both a rating and a confidence score in a single response?

Accepted Answer

Define a tool with an 'input_schema' containing required 'rating' and 'confidence' properties and force tool use.. A tool definition with an 'input_schema' that marks 'rating' and 'confidence' as required, combined with forced tool use, guarantees both fields appear in a single structured tool call. This keeps the rating and its confidence score aligned and eliminates parsing ambiguity. Few-shot examples and prose instructions only influence behavior and cannot enforce required fields.

Answer

Include a few-shot example showing a JSON object with both keys and ask Claude to follow it exactly.

Answer

Ask for a JSON object with 'rating' and 'confidence' keys and parse the text response.

Answer

Use two separate prompts: one for rating and one for confidence, then merge the results.

Question 14

A developer new to Claude Code wants to quickly see a list of all available slash commands in their current session. Which command should they use?

Accepted Answer

/help. The /help command is the standard way to list all available slash commands and get assistance within Claude Code. It provides a comprehensive overview of both built-in and custom commands. Other suggested commands like /commands, /list, or /menu are not recognized by Claude Code and would not fulfill the developer's request.

Answer

/commands

Answer

/list

Answer

/menu

Question 15

You are designing a customer support assistant that must always respond in a calm, professional tone. During testing, you notice that after several turns of heated user complaints, Claude's replies become abrupt and less empathetic. You need the most reliable way to prevent this tonal drift throughout a long conversation. What should you do?

Accepted Answer

Use a system prompt that explicitly defines the persona and tone, and keep it unchanged across all turns.. Tonal drift in long conversations is best mitigated by placing the desired persona and tone in the system prompt, which Claude treats as a persistent instruction set. Unlike user-turn reminders or hidden assistant turns, the system prompt remains constant and authoritative, helping the model maintain consistent behavior even when user messages are emotionally charged. Lowering temperature affects randomness, not persona adherence.

Answer

Reduce the model's temperature to 0 so that responses become deterministic and tone cannot vary.

Answer

Add a reminder of the desired tone at the beginning of each user message.

Answer

After each user message, insert a hidden assistant turn that models the desired tone.

Question 16

An architect is reviewing an MCP server's tool catalog before release. The team wants to reduce the chance that Claude selects the wrong tool when several tools have overlapping purposes, and to make failures easier to diagnose. Which two changes best support those goals? (Choose two.)

Accepted Answer

Return errors from tools as structured objects with a stable code and a human-readable message.. Tool selection quality comes from clear, distinct names and descriptions, while diagnosis quality comes from structured, coded errors. Together they reduce wrong-tool calls and make remaining failures easy to trace. Merging tools, expanding the catalog, or relying on implicit reasoning all move in the wrong direction for these two goals.

Answer

Merge all overlapping tools into one function with a `mode` parameter that selects behavior internally.

Answer

Rely on the model's general reasoning to disambiguate similar tools without changing names or descriptions.

Answer

Increase the number of tools in the catalog so the model has a fallback for every conceivable case.

Question 17

A platform team wants Claude Code to be allowed to run only a specific set of safe Bash commands (for example, `npm test` and `git status`) without prompting, while still blocking arbitrary shell commands. They want this policy applied automatically to every developer who clones the repository. Where should they define this allowlist so it is version-controlled and enforced for the whole team?

Accepted Answer

In the project's .claude/settings.json file committed to the repository. Project-scoped settings live in .claude/settings.json inside the repository and are committed to version control, so every developer automatically inherits the same permission allowlist. User-scoped settings apply only locally, environment files are not parsed by Claude Code, and CLAUDE.md provides advisory context rather than enforceable permissions.

Answer

In a .env file at the repository root

Answer

In the user's ~/.claude/settings.json file

Answer

In the CLAUDE.md file at the repository root

Question 18

A data-engineering team uses Claude to normalize product descriptions into a fixed set of attributes. Their few-shot examples all come from the electronics catalog, and accuracy is high there, but when the same prompt is applied to apparel listings the model mislabels attributes. They want to improve apparel accuracy without degrading electronics results. Which approach best addresses the problem?

Accepted Answer

Add a small number of diverse, correctly labeled few-shot examples drawn from apparel alongside the existing electronics examples.. Few-shot examples define the distribution the model imitates, so the electronics-only set teaches electronics patterns and fails on apparel. Adding a few correctly labeled apparel examples introduces the missing patterns while keeping the electronics demonstrations that already work, improving the weak domain without harming the strong one. Sampling and prompt-length changes do not broaden domain coverage.

Answer

Lower the temperature to 0.0 and keep the existing electronics-only example set unchanged.

Answer

Raise the number of electronics examples from four to twenty so the model has more evidence about how attributes are labeled.

Answer

Remove all few-shot examples and rely solely on detailed prose definitions of each attribute.

Question 19

You are architecting a customer-support assistant that maintains a persistent knowledge base across sessions. After several weeks, users report that the assistant confidently cites policy details that were never in the source documents. Which architectural change most directly addresses this reliability failure?

Accepted Answer

Require the assistant to answer only from retrieved passages and to return a sentinel value when retrieval yields no supporting passage.. The reported failure is unsupported factual claims, so the fix must tie answers to verifiable source content. Constraining the assistant to retrieved passages and defining a no-answer sentinel gives the system an explicit grounding contract and a detectable failure state. Determinism settings, longer outputs, and accuracy exhortations change style or length but never establish whether a cited policy actually exists.

Answer

Increase the max_tokens parameter so the assistant has more room to explain its reasoning before answering.

Answer

Add a system prompt instruction telling the assistant to never make mistakes and to always be accurate.

Answer

Lower the temperature parameter to zero so the assistant produces more deterministic responses.

Question 20

A consultant is preparing a Claude Code setup for a client whose repository must never send secrets to the model. The consultant wants to block reads of `.env` files and any file under a `secrets/` directory at the tool level. Which configuration achieves this?

Accepted Answer

Add `Read(./.env)` and `Read(./secrets/**)` deny rules to the permissions block in `.claude/settings.json`.. Claude Code permission rules are evaluated by tool and path pattern, and deny rules take effect before the tool executes. Denying `Read` for `.env` and `secrets/**` in the project settings ensures the assistant cannot open those files even if a prompt asks for them, providing the tool-level enforcement the security requirement demands.

Answer

Set file permissions with `chmod 000` on `.env` and the `secrets/` directory so the assistant cannot open them.

Answer

Instruct the assistant in `CLAUDE.md` to never open `.env` files or anything inside `secrets/`.

Answer

List `.env` and `secrets/` in a `.claudeignore` file at the repository root so Claude Code skips them.