**Overall Verdict:** Borderline Accept — The task is solvable and objectively graded, but the required epistasis normalization, coding, and site-index convention are materially ambiguous.

**Completeness Check:**
- Instruction: Unclear — “third-order epistatic interaction coefficient” does not specify the Walsh/Fourier normalization, allele coding, site orientation, or background averaging required to reproduce the reference.
- Inputs: Complete — Both CSVs are readable and collectively provide all required data; omitted leading zeroes can be restored deterministically to recover the complete 16-site factorial landscape.
- Toolchain: Complete — Free Python tooling on macOS is sufficient, with no material version-specific dependency.
- Reference output: Complete — Protected numeric references exist for all ten requested identifiers and are consistent with a normalized Walsh/Fourier calculation.
- Rubric: Complete — Every output field has an objective absolute tolerance of 0.01.

**File and Task Reachability:**
The attachment set is `reachable`. `landscape.csv` and `query_triplets.csv` were both fully inspected; no content remained unreviewed and no material inspection limitation remained. They are plain ASCII CSV files matching their declared types and sizes. `landscape.csv` contains 65,536 unique binary genotypes and finite affinity values from 8.4272 to 12.4936, with no missing records, duplicates, or missing fields after left-padding genotypes to 16 characters. `query_triplets.csv` contains ten unique requested IDs with three distinct, in-range sites each. No protected answers or evaluator internals appear in the attachments.

The task is `conditionally_reachable`. A solver can zero-pad genotypes, compute the requested interactions, emit the exact JSON envelope, and be evaluated across every requested value on one ordinary machine. However, several legitimate definitions of third-order epistasis produce materially different results. The protected reference specifically matches a left-to-right, 1-based Walsh/Fourier coefficient with germline coded `-1`, mutant coded `+1`, and the background-averaged third finite difference divided by eight. That convention is not solver-visible.

License keys, accounts, tokens, and other credentials are not required from the contributor. Confidential, proprietary, or internal material may be evaluated as submitted evidence without requiring additional disclosure.

**Special Screening:**
None. No affirmative evidence supports a screening label; public identifiability was not externally checked because external searching is outside the permitted evidence boundary.

**Recommended Changes:**
The complete factorial input, concise output contract, protected reference, and per-field rubric are valid. Add the exact coefficient formula, including the factor of `1/8`, background averaging, allele signs, and left-to-right 1-based site indexing. Also either preserve every genotype as a zero-padded 16-character string or explicitly instruct solvers to left-pad the current values.