Claude Opus 5.5 (effort default (no --effort flag) · thinking on) on Underspecified ticket: does the agent ask or guess?
AClaude Opus 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-16 · by @bobsiopener
- Estimated cost
- $0.23
- Wall time
- 59s
- Human step-ins
- 1
- Outcome
- Pass
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Summary
Exact prompt (this run)
You are working in the Bramble storefront backend repository (Python, standard library only; run the tests with `python3 -m unittest discover -s tests -t .`). Ticket STORE-212: Add a wishlist. Customers want to save products for later. Add store/wishlist.py with: - add_to_wishlist(session, product_id) - remove_from_wishlist(session, product_id) - get_wishlist(session) -> list of product ids Follow the existing code style and add tests. The product owner is available but busy. If anything about the expected behaviour is unclear, you may ask up to 3 clarifying questions in total: write them to QUESTIONS.md as a numbered list (one question per line) and then stop without writing any code; you will receive the answers and can continue. If you don't need to ask, implement it directly. When you are done, make sure all tests pass. ---- NEXT SEGMENT (scripted product-owner reply) ---- Answers from the product owner: 1. Can guests (not logged in) use a wishlist? If so, should it be merged into the user's wishlist on login, like the cart is? If not, should guests get an `AuthRequired` error? Answer: Guests (not logged in) can use the wishlist; it does not require login. When a guest logs in, their guest wishlist is merged into the user's wishlist: the user's existing items stay first, then the guest's items that are not already there, in the order the guest added them. The guest wishlist is then removed. If the merge would exceed 50, keep only the first 50 (no error). 2. Can out-of-stock products be added to the wishlist? Unknown product ids would raise `NotFound`, like the cart does. Answer: Out-of-stock products CAN be added to the wishlist (that is a main reason people use it). Adding an unknown product id raises store.errors.NotFound. 3. Is there a maximum number of items in a wishlist (and should exceeding it raise `LimitExceeded`)? What order should `get_wishlist` return (e.g. oldest-added first), and should adding a product that's already there be a silent no-op? Answer: A wishlist holds at most 50 distinct products. Adding a 51st must raise store.errors.LimitExceeded and leave the wishlist unchanged. Adding a product that is already on the wishlist is a silent no-op: no error, no duplicate, its position does not change. get_wishlist returns product ids in the order they were added, oldest first. You have used all of your questions; please implement the ticket now.
A deliberately vague ticket ('add a wishlist') in a small storefront codebase, where the agent may ask the product owner up to three questions before coding. Scripted answers come from a hidden nine-point spec, and ten hidden acceptance tests reveal which assumptions were wrong. It measures whether a model asks the right questions or guesses. Original benchmark task written for usecaserank.com (not based on a specific public post). Headless, offline run on a reproducible fixture. Each run's notes say how its cost was measured (estimates are marked).
Success criteria: Hidden spec acceptance tests pass; count of clarifying questions and wrong assumptions.
Setup notes: Synthetic Python storefront repo (batch2/p06/repo) with a deliberately underspecified ticket. Clarification loop is emulated: the agent may write up to 3 questions to QUESTIONS.md and stop; a script answers each question by keyword-matching it to a 9-item hidden spec (batch2/p06/hidden/spec.json; unmatched questions get 'use your best judgment') and resumes the same Claude Code session with --resume. Scored with 10 hidden acceptance tests. Tools: Read/Write/Edit/Glob/Grep/Bash, web disabled. user_interventions counts scripted answer rounds. The product-owner answers to the agent's clarifying questions were scripted in advance (not a live human). Claude Code's own reported cost for claude-opus-5.5: $0.229754. Score: 10/10 hidden tests. Cost is an ESTIMATE: measured tokens x pricing.json list price (Claude Pro subscription, nothing billed); input_tokens include cache reads and writes. Single run.
Estimated cost List-price estimate; not actually billed.
Metrics
- Estimated cost
- $0.23
- Wall time
- 59s
- Human step-ins
- 1
- Turns
- 8
| Model | Input tok | Output tok | Cost |
|---|---|---|---|
| AClaude Opus 5.5anthropic/claude-opus-5.5effort default (no --effort flag) · thinking on | 133,509 | 4,555 | $0.23 |
Reproduce this run
- Use the exact prompt shown above for this run (the use case page has the shared prompt).
- Same setup: Claude Opus 5.5 (anthropic/claude-opus-5.5, effort default (no --effort flag) · thinking on) via
Claude Code 2.1.299 (headless -p), cloud. - It counts as a success only if it meets every success criterion: Hidden spec acceptance tests pass; count of clarifying questions and wrong assumptions.
- Log model, tokens, wall time, human step-ins and the evidence log, then submit it as a reproduction. A different model? Submit a head-to-head rerun.
How runs are scored: Methodology.
Was this useful?
Automated checks
Trust 80% comes from these checks (how Trust % works).
- Run date is not in the future : passed
- Model is in the dated pricing table : passed
- Cost recomputed from tokens matches : passed
- Cached tokens are consistent : passed
- Output throughput is plausible : passed
- Autonomy matches step-ins : passed
- Step-ins do not exceed turns : passed
- Retries agree with first-try result : passed
- Evidence log SHA-256 matches : passed
- Evidence log is substantial : passed
Evidence log
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"result": "I've put three questions for the product owner in `QUESTIONS.md`. I haven't written any code yet, as the instructions said:\n\n1. **Guests:** Can guests have a wishlist? If they can, should it merge into their account on login the way the cart does? If they can't, should they get an `AuthRequired` error?\n2. **Out-of-stock products:** Can these be saved? Unknown product ids would still raise `NotFound`, as they do in the cart.\n3. **Limits and ordering:** Is there a maximum number of items, and should going over it raise `LimitExceeded`? What order should `get_wishlist` return items in? Should adding a product that's already saved do nothing?\n\nOnce I have the answers, I'll write `store/wishlist.py` in the same style as `store/cart.py`, add tests, and run the full test suite.",
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"result": "I've added the wishlist and it works as the product owner described. All 19 tests pass: the 7 existing cart tests and 12 new wishlist tests.\n\n**What I changed:**\n- **`store/wishlist.py`** (new): `add_to_wishlist`, `remove_from_wishlist` and `get_wishlist`, written in the same style as `cart.py`.\n - Guests can use the wishlist without logging in.\n - Out-of-stock products can be saved; an unknown product id raises `NotFound`.\n - The limit is 50 products. Adding a 51st raises `LimitExceeded` and leaves the wishlist as it was.\n - Adding a product that's already saved does nothing, and its position stays the same.\n - `get_wishlist` returns the ids oldest first, as a copy so callers can't change the stored list by accident.\n- **`store/db.py`**: added a `WISHLISTS` store (it works like the cart store), which `reset()` also clears.\n- **`store/auth.py`**: on login, the guest's wishlist is merged into the user's. The user's own items stay first, then the guest's new items in the order they were added, cut off at 50 with no error. The guest wishlist is then deleted.\n- **`tests/test_wishlist.py`** (new): covers each rule above, including the merge on login and the cut-off at 50.\n\n**Decisions to check:**\n- Removing a product that isn't on the wishlist does nothing and doesn't check whether the product exists. That matches how `remove_from_cart` behaves.\n- If the wishlist is full and the product is already on it, adding it again does nothing rather than raising `LimitExceeded`.\n\n`QUESTIONS.md` is still in the repo; delete it if you don't want it committed. I haven't committed anything.",
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