CCAO-F Using the Claude API Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Set the temperature parameter to 1.0 and rely on the model's natural tendency to produce structured output.

  Why it's wrong here

  Temperature controls randomness, not output structure. Setting it to 1.0 increases variability, which makes strict JSON conformance less reliable, not more. The model may still wrap the JSON in prose or add trailing commentary. This parameter does not enforce a schema or suppress natural language around the object, so it fails to meet the requirement of returning only valid JSON.

• ✗

  Add the instruction 'Return only JSON, nothing else' to the system prompt and set max_tokens to a small value.

  Why it's wrong here

  Prompt instructions alone do not guarantee strict conformance; the model may still add markdown fences or explanatory sentences. Limiting max_tokens can truncate the JSON mid-object, producing invalid output. This approach depends on probabilistic compliance rather than a structural constraint, so it cannot reliably deliver schema-valid JSON with no extra prose in a production scenario.

• ✓

  Use the tool_choice parameter set to {"type": "tool", "name": "your_tool"} with an input_schema defining the desired JSON structure.

  Why this is correct

  Forcing a specific tool with tool_choice directs the model to emit a tool_use block whose input conforms to the supplied input_schema, effectively producing structured JSON. This is the documented mechanism for schema-constrained outputs in the Messages API. It reliably yields a parseable JSON object matching the schema rather than free-form prose, which satisfies the strict conformance requirement.

• ✗

  Set the stop_sequences parameter to ['}'] so the response terminates immediately after the closing brace.

  Why it's wrong here

  A stop sequence of '}' would halt generation at the first closing brace, which may occur inside a nested object or string, truncating the JSON. It does not enforce a schema and can produce incomplete structures. Stop sequences control when generation ends, not what shape the output takes, so this configuration is unsuitable for guaranteeing valid, complete JSON.