Anthropic CCAR-F Claude Certified Architect – Foundations Exam Practice Test

This change is narrow, localized, and already defined: add one conditional validation check to an existing function in a single file. A separate planning phase would introduce process overhead without resolving meaningful architectural uncertainty. Direct execution allows Claude to read the function, implement the condition, and run the relevant focused tests.

Anthropic explicitly states that plan mode adds overhead and should generally be skipped when the scope is clear and the fix is small. Planning is most valuable when the approach is uncertain, multiple files are affected, or the code is unfamiliar. Anthropic’s practical rule is that when the required diff can be described in one sentence, direct implementation is appropriate. ( https://code.claude.com/docs/en/best-practices )

Option B allocates unnecessary reasoning effort to straightforward validation logic. Options C and D exaggerate the complexity of a single-function change. Broader impact analysis would be justified only if the requirement altered reservation semantics, time-zone rules, persistence behavior, or public interfaces—none of which is stated.

The implementation should still include verification. Claude should add or update tests for a future date, the current date, and a past date, then run the narrowest relevant test command. Direct execution does not mean unverified execution.

Official references/topics: Direct Execution; Plan-Mode Selection; Small Scoped Changes; Focused Verification.

Resuming preserves the prior architectural analysis, dependency mapping, and conversation history, avoiding the cost of repeating an hour of valid work. Anthropic states that resuming by session ID restores the agent’s full prior context, including files read, analysis performed, and decisions made. ( https://code.claude.com/docs/en/agent-sdk/sessions )

However, the session represents historical knowledge rather than a repository snapshot. Because three files changed externally, the agent must be told which files are affected and directed to re-read them before relying on earlier conclusions. Anthropic clarifies that sessions persist the conversation, not the filesystem. ( https://code.claude.com/docs/en/agent-sdk/sessions ) Targeted re-analysis updates the stale portion of the agent’s model while retaining the nine unchanged files’ established context.

Option A discards valuable work even though most of the analyzed code remains unchanged. Option C is accurate but inefficient because it reprocesses all twelve files regardless of whether they changed. Option D is unsafe: the agent may continue reasoning from obsolete function signatures, dependencies, or control flows.

The continuation prompt should identify the changed files, summarize the merge’s purpose where known, and request a focused comparison against the earlier understanding. Any architectural conclusions affected by those changes should then be revised explicitly.

Official references/topics: Session Resume; Filesystem Versus Conversation State; Targeted Re-Analysis; Repository Change Awareness.

In the standard Claude tool-use loop, the application executes lookup_order and sends its output back as a tool_result . That result becomes part of the conversation state available to Claude. Claude then evaluates the purchase date, refund policy, customer request, authorization constraints, and available tools before selecting the next action.

Anthropic describes client-tool orchestration as a repeated loop: Claude emits a tool_use request, the application executes it, returns a tool_result , and Claude continues reasoning from the updated conversation. Claude, rather than the tool implementation, selects when and how to invoke the next available tool unless the application has explicitly implemented a fixed workflow. ( https://platform.claude.com/docs/en/agents-and-tools/tool-use/how-tool-use-works )

Options B and C describe possible custom orchestration architectures, but neither is stated in the scenario. Option D is inconsistent with adaptive agent behavior because later actions depend on information that did not exist before lookup_order completed. A rigid sequence would not respond appropriately to different purchase dates, eligibility states, or order conditions.

The tool result should return high-signal fields such as purchase date, return-window status, refund eligibility, existing refund status, and stable order identifiers so Claude can make the subsequent decision accurately.

Official references/topics: Tool-result continuation, adaptive agent loops, model-directed tool selection, sequential dependency handling.

Forking the existing analysis session creates independent continuations that inherit the accumulated conversation context. Each branch begins with the same understanding of the service module, request flow, source files, and error-handling patterns, but subsequent work on one testing strategy does not alter the other branch or the original session.

Anthropic’s Agent SDK documentation states that sessions can be resumed with their full context and forked to explore different approaches. In the SDK, enabling fork_session while resuming causes the continuation to receive a new session identifier rather than modifying the original session. ( https://docs.anthropic.com/en/docs/claude-code/sdk?utm_source=chatgpt.com )

Option B wastes time, tokens, and tool calls by requiring both new sessions to rebuild the same 23-file analysis. Option C mixes two experimental implementations into one conversation, increasing the risk that assumptions, edits, or conclusions from the first strategy influence the second. Option D preserves only a manually selected summary, which may omit details contained in the full session history.

The appropriate design is to create one fork for the end-to-end strategy and another fork for the snapshot strategy. The original analysis remains a stable parent, while each child session develops and evaluates its approach independently.

Official references/topics: Agent SDK Sessions, Session Forking, Context Preservation, Alternative-Approach Evaluation.

The error response must explicitly communicate both control semantics and user-facing meaning. Setting "retriable": false tells the agent that repeating the same operation cannot change the outcome. Providing a customer-friendly explanation allows Claude to respond accurately without exposing internal implementation details or inventing its own interpretation of the business rule.

Anthropic recommends returning failed tool operations with an error indicator and sufficiently informative content so Claude can decide whether to retry, request another input, or explain the limitation. Tool interfaces should provide detailed descriptions and structured parameters rather than forcing Claude to infer operational behavior from ambiguous text. ( https://platform.claude.com/docs/en/agents-and-tools/tool-use/build-a-tool-using-agent?utm_source=chatgpt.com )

Option A appropriately limits automatic retries to technical failures, but it does not solve the stated customer-response problem unless business failures also carry clear semantics. Option B relies on fragile parsing of human-readable messages. Option C adds latency and another tool dependency, and eligibility may still change or fail for reasons not covered by the preliminary check.

A complete schema should identify the error code, category, retryability, customer-safe explanation, and permitted next actions. Technical errors can similarly return "retriable": true with retry guidance and a maximum-attempt policy.

Official references/topics: Structured tool errors, retryability classification, customer-safe explanations, resilient MCP contracts.

Prompt chaining is appropriate because the workflow consists of predictable, fixed subtasks that apply to every pull request. The system can run a focused style-compliance analysis, then a security analysis, then a documentation review, and finally synthesize the three results into a consistent report.

Anthropic defines prompt chaining as decomposing a task into a sequence of steps in which each call handles a smaller component. It is recommended when a task can be cleanly divided into fixed subtasks, trading additional latency for better focus and accuracy. Intermediate checks can also be inserted between stages to confirm that each report section meets its requirements. ( https://www.anthropic.com/engineering/building-effective-agents )

Option A concentrates all considerations into one call, making it easier for one aspect to receive inadequate attention. Option B is unnecessary because orchestrator-workers is intended for complex work where the required subtasks cannot be predicted in advance. Here, the three review dimensions are already known and remain constant. Option D solves a different problem: routing is appropriate when inputs belong to distinct categories that require different downstream processes.

Although the three analyses could potentially be parallelized for lower latency, the option that accurately represents the stated repeatable decomposition is prompt chaining with final synthesis.

Official references/topics: Prompt Chaining, Fixed Subtasks, Intermediate Validation, Workflow Selection.

This migration is a high-impact, cross-module change with several independent breaking changes. Before editing, Claude must determine how the callback-based API is currently used, where the restructured User fields propagate, whether deprecated methods are wrapped or re-exported, and which downstream modules depend on the affected behavior. Plan mode is therefore the correct starting point because it allows Claude to inspect the repository, identify affected code paths, and produce an implementation strategy without modifying source files.

Anthropic recommends separating exploration and planning from implementation when the approach is uncertain, the change affects multiple files, or the developer is unfamiliar with the impacted code. Direct execution is better reserved for small, clearly scoped changes that can be described as a simple diff. ( https://code.claude.com/docs/en/best-practices )

Option A applies transformations before establishing whether every usage follows the same pattern. Option B turns the test suite into a reactive discovery mechanism and may miss untested behavior. Option D provides useful migration documentation but assumes all 45 files can be changed uniformly. The reliable sequence is exploration, impact mapping, migration planning, implementation, and verification against tests and type checks.

Official references/topics: Plan Mode; Explore–Plan–Implement Workflow; Multi-File Migration Planning; Verification.

The task is open-ended because neither the critical modules nor the required testing sequence is known in advance. The agent should first use lightweight discovery tools to map the repository, locate existing tests, identify central modules, and determine which components have high fan-in, business significance, complex branching, or extensive external dependencies. It can then produce an initial risk-based testing plan and refine it as new dependency information appears.

Anthropic distinguishes predefined workflows from agents that dynamically control their processes and tool usage. Agents are appropriate when the required steps cannot be reliably hardcoded and must adapt to environmental evidence. During execution, they should obtain ground truth through tool results and use that feedback to determine subsequent actions. ( https://www.anthropic.com/research/building-effective-agents ) Anthropic also identifies orchestrator-worker designs as suitable for complex coding and search tasks where the necessary subtasks depend on what the investigation reveals. ( https://www.anthropic.com/research/building-effective-agents )

Option A assigns effort using directory boundaries rather than risk. Option C exhausts context before delivering value. Option D uses alphabetical order, which has no relationship to impact or coverage priority.

Option B establishes an evidence-driven decomposition: discover, prioritize, test high-impact paths, measure results, and revise the plan as dependencies and uncovered risks emerge.

Official references/topics: Dynamic Task Decomposition; Adaptive Agent Loops; Orchestrator-Workers; Risk-Based Test Planning.

Forking is specifically designed for exploring alternative directions from a shared body of prior analysis. Each fork starts with a copy of yesterday’s conversation history, including the files read, architectural observations, dependency findings, and decisions already recorded. The microservice approach and the in-place refactoring approach can then develop independently under separate session IDs.

Anthropic’s Agent SDK documentation states that a fork creates a new session from a copy of the original history while leaving the original session unchanged. Each resulting session can subsequently be resumed independently. The documented implementation combines resume with fork_session=True in Python or forkSession: true in TypeScript. ( https://code.claude.com/docs/en/agent-sdk/sessions )

Option B allows conclusions, assumptions, and proposed edits from the first approach to contaminate the evaluation of the second. Option C preserves context for only one branch and forces the engineer to reconstruct context manually for the other. Option D discards the detailed analysis already captured in the session and depends on potentially incomplete summaries.

Two forks provide equivalent starting conditions, preserve the parent investigation, and support a fair comparison of scope, migration risk, operational complexity, and required code changes. Filesystem edits should still be isolated through worktrees or checkpointing because session forking branches conversation history, not the working directory.

Official references/topics: Agent SDK Sessions; Session Forking; Alternative-Approach Exploration; Context Preservation.

The most reliable architecture separates semantic interpretation from deterministic normalization. Claude is well suited to identifying that “$12” and “12.00” represent prices, or that a leaf icon represents a dietary classification. However, canonical conversion—removing currency symbols, converting values to decimal types, mapping icons to controlled labels, and enforcing locale-specific rules—is more predictably performed in application code.

Structured Outputs guarantee that Claude returns valid JSON matching the supplied schema, but that guarantee concerns structural conformance. It does not by itself guarantee that every semantically equivalent source representation will be normalized identically. Anthropic’s evaluation guidance identifies code-based checks as the fastest, most reliable, and most scalable mechanism for rule-based validation. ( https://platform.claude.com/docs/en/build-with-claude/structured-outputs )

Option D therefore minimizes model responsibility: Claude extracts the evidence as represented, and deterministic post-processing converts it into the canonical downstream format. This also makes normalization rules independently testable, version-controlled, and auditable.

Option A increases latency and cost without solving normalization. Option B improves output structure, but prompt-based normalization can still vary across ambiguous formats. Option C introduces unnecessary stochasticity and majority-vote logic where explicit parsing rules are available. The downstream contract should remain stable, but format conversion should be implemented using deterministic transformations rather than repeated probabilistic inference.

Official references/topics: Structured Outputs—schema compliance; Evaluation Design—code-based validation; Reliable extraction pipelines.

MCP allows a Claude application to connect to multiple servers and expose their enabled tools within the same agentic interaction. Anthropic’s MCP connector documentation explicitly supports connecting to multiple MCP servers in one request. Once connected, Claude can invoke a server’s tool when the user’s request corresponds to the capability described by that tool. ( https://docs.anthropic.com/en/docs/agents-and-tools/mcp-connector )

In this scenario, the git server can provide the branch-creation operation, the documentation server can locate the relevant links, and the Jira server can update ticket JIRA-123. The agent can coordinate these capabilities without requiring a separate conversational turn that restricts it to only one server. Tool descriptions and schemas tell Claude what each operation does and what inputs it requires.

Option B incorrectly describes sequential capability discovery. Server identity and tool definitions are established through the MCP configuration rather than discovered by querying every server for each operation. Option C is incorrect because connecting several servers does not inherently restrict the agent to a single selected server. Option D imposes a one-server-per-turn limitation that MCP does not require.

Access can still be controlled through allowlists, denylists, permissions, and per-tool configuration. Those controls restrict which tools are enabled; they do not change the fundamental ability to make tools from multiple configured servers available together.

Official references/topics: MCP Server Configuration, Multi-Server Tool Access, Tool Discovery, MCP Tool Permissions.

The investigation path cannot be reliably predetermined because the responsible files, components, and execution sequence are unknown. The agent should begin with available evidence—such as route definitions, stack traces, logs, or endpoint references—and use each discovery to decide the next search, file read, or diagnostic action.

Anthropic distinguishes predefined workflows from agents that dynamically direct their own processes and tool usage. Agents are appropriate for open-ended problems where the required number and nature of the steps cannot be predicted or encoded as a fixed path. During execution, the agent should obtain ground truth from tool results and adapt its plan based on that environmental feedback. ( https://www.anthropic.com/engineering/building-effective-agents )

Option A requires a comprehensive plan before the agent has inspected the code, so the plan would rest on unsupported assumptions. Option B forces every investigation through the same sequence even when an early discovery makes later steps irrelevant or identifies a different dependency path. Option C assumes the four layers can be investigated independently; tracing an intermittent request failure usually involves dependencies revealed sequentially across layers.

Option D implements an adaptive agent loop: inspect, form a hypothesis, use tools, evaluate the evidence, and generate the next subtask. The workflow should still include stopping conditions, testable hypotheses, and escalation when evidence remains inconclusive.

Official references/topics: Adaptive Agent Loops, Dynamic Task Decomposition, Tool Feedback, Open-Ended Coding Investigations.

The agent is behaving inconsistently because every failure is represented identically. “Operation failed” contains no information about permanence, user correctability, authorization, or whether another attempt is likely to succeed. Adding structured fields converts the error into an actionable interface contract.

Anthropic instructs tool implementations to mark failures using an error flag and return information Claude can use to retry with corrected input, ask for clarification, or explain a limitation. Tool design should expose sufficient detail for the model to choose the correct next action rather than forcing it to infer the cause from a generic message. ( https://platform.claude.com/docs/en/agents-and-tools/tool-use/build-a-tool-using-agent?utm_source=chatgpt.com )

With error_category , isRetryable , and a causal description, the agent can retry transient network failures, request corrected identifiers for validation errors, and escalate or report permission failures without pointless repetitions. Option B retries permanent validation and permission failures unnecessarily. Option C adds another tool call and failure point merely to classify information the original tool already possesses. Option D relies on parsing variable text and examples rather than providing explicit machine-readable semantics.

The tool should preserve isError: true , return a stable structured error object, include a safe customer-facing message where appropriate, and avoid exposing internal secrets or stack traces.

Official references/topics: MCP error contracts, actionable tool results, retryability metadata, agent-computer interface design.

A tool definition converts the desired extraction structure into an explicit machine-readable contract. Claude returns the event information inside a tool_use block, with the tool arguments corresponding to the properties defined by the tool’s input_schema . Anthropic specifies that custom tool parameters are described using JSON Schema, allowing the application to extract the structured arguments directly rather than attempting to recover JSON from ordinary prose. For current implementations, adding strict: true to the tool definition provides guaranteed conformance of tool-call inputs to the declared schema. ( https://docs.anthropic.com/en/docs/agents-and-tools/tool-use/implement-tool-use )

Options A, B, and D remain prompt-based formatting techniques. They may improve the probability of valid JSON, but none creates the same schema-enforced interface. Prefilling an opening brace constrains the beginning of the response without guaranteeing valid field names, required properties, or data types. Retry logic detects failures only after generation and adds latency. Detailed formatting instructions can still produce malformed or structurally incorrect output.

Anthropic now also provides Structured Outputs for direct, schema-validated JSON responses. Within the options presented, however, a schema-defined tool is the only approach that establishes an explicit structured-output boundary rather than relying primarily on text-generation compliance. ( https://docs.anthropic.com/en/docs/test-and-evaluate/strengthen-guardrails/increase-consistency )

Official references/topics: Tool Definitions, JSON Schema Input Contracts, Strict Tool Use, Structured Outputs.

The root cause is an incomplete tool contract. Claude sees that process_refund requires an order_id , but the tool description does not explain the parameter’s trusted source or the prerequisite lookup sequence. Option A makes the dependency explicit and prohibits fabricated values.

Anthropic states that tool descriptions should explain what a tool does, when it should be used, how it behaves, and any important limitations. Its prompting guidance also states that dependent tool calls must be executed sequentially and that Claude must never use placeholders or guess missing tool parameters. ( https://platform.claude.com/docs/en/agents-and-tools/tool-use/define-tools )

Option B merely forces some tool use; it does not force the correct tool or prevent a fabricated identifier. Option C is an essential defense-in-depth control, but it detects the invalid ID after the model has already made the faulty call. It does not correct the selection logic that caused the fabrication. Option D works only when the customer actually provides an identifier and introduces an unnecessary preprocessing dependency.

The process_refund schema should describe order_id as a verified identifier returned by lookup_order , and the tool description should state that the tool is unavailable until the corresponding order has been retrieved and eligibility established.

Official references/topics: Tool descriptions, prerequisite tool calls, parameter provenance, sequential tool orchestration.

Limited review capacity should be concentrated on records with the highest probability of semantic error. Schema validation confirms that the response has the correct structure and data types; it does not establish that the extracted values are accurate. Ambiguous wording, contradictory passages, missing evidence, and model-reported uncertainty are direct indicators that an extraction requires human judgment.

Anthropic’s reliability guidance recommends permitting Claude to express uncertainty, grounding factual outputs in source material, and validating critical information because hallucination-reduction methods do not eliminate errors completely. These principles support routing uncertain or evidentially conflicted records to reviewers rather than treating syntactically valid output as automatically trustworthy. ( https://docs.anthropic.com/en/docs/test-and-evaluate/strengthen-guardrails/reduce-hallucinations )

Option B may waste reviewer capacity on clear, well-supported values while overlooking ambiguous errors in other fields. Option C is reactive: downstream acceptance does not guarantee semantic correctness, and silent errors may never produce processing failures. Option D provides an unbiased estimate of overall quality and should be retained as a secondary audit mechanism, but random selection is not the most efficient way to intercept risky records when only 5% can be reviewed.

In production, model confidence should not be treated as a calibrated probability by itself. It should be combined with objective signals such as contradictory source spans, missing citations, OCR quality, validation warnings, document type, and business impact.

Official references/topics: Human-in-the-Loop Review, Uncertainty Handling, Source Grounding, Risk-Based Escalation.

The correct objective is to construct an architectural map before consuming the full implementation. Identifying the base cache abstraction, its interface, and the classes that implement or invoke it gives the agent a dependency-guided path through the code. It can then inspect only the invalidation implementations and integration points relevant to the proposed trigger.

This approach protects the context window. Anthropic states that every file read occupies context and that model performance can deteriorate as the window fills. Its Claude Code guidance warns against unbounded investigation that reads large numbers of files and recommends narrowing the exploration or delegating it. ( https://code.claude.com/docs/en/best-practices )

Option A is too lexical: searching only for invalidate or expire can miss event-driven invalidation, overridden methods, cache-key mutation, and generic interface calls. Option B loads approximately 6,000 lines without first establishing relevance. Option C assumes that filename patterns and file size correlate with architectural importance; the largest files may contain incidental code while a small interface defines the entire design.

Option D follows control and type relationships rather than arbitrary file order. After reading the base class, the agent can search for subclasses, imports, construction sites, middleware hooks, and calls to the invalidation contract, progressively expanding only where evidence requires it.

Official references/topics: Context-Efficient Exploration; Dependency-Guided Reading; Architectural Interfaces; Narrowly Scoped Investigation.

Option B removes the ambiguity from the tool interface itself. The agent no longer needs to choose between separate functions that represent closely related business operations. Instead, a single compensation tool exposes an explicit action parameter, while the existing order lookup tool can optionally return delivery-tracking information through a clearly defined flag.

Anthropic’s tool-design guidance recommends consolidating related operations into fewer, more capable tools when separate functions create unnecessary semantic overlap. Claude selects tools primarily from their names, descriptions, schemas, and the current task. When multiple tools appear capable of satisfying the same request, selection accuracy declines because the agent must infer distinctions that should have been made explicit in the interface design.

Option A adds routing complexity but leaves overlapping financial operations available within the same sub-agent. Option C reduces the number of tools loaded initially, but it does not eliminate the semantic duplication between compensation operations or overlapping lookup functions. Option D may improve behavior through examples, but it compensates for a poorly designed tool surface rather than correcting the root cause.

The consolidated schemas should use enums for supported actions, clearly define when each action applies, and document the returned fields. This creates a smaller and more deterministic agent-computer interface.

Official references/topics: Tool consolidation, semantic tool boundaries, action parameters, MCP tool-selection accuracy.