FA-99801 / Tool call schema validation / Open access

Nested required fields are checked on the outer object · case 01

Nested required fields are checked on the outer object.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

A nested requirement is mistakenly looked up at the root.

THE FAILURE

A nested requirement is mistakenly looked up at the root.

Unsuccessful approach: Checking only the immediate child fails for paths of depth greater than one.

Case contract

For a path of keys, return true only when every key exists and the terminal mapping contains the required key.

Why this case matters

Tool argument validation prevents malformed structured payloads from entering a deterministic downstream operation.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(obj, path, required):
    return required in obj
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('depth three',solve({'a':{'b':{'c':N}}},['a','b'],'c'),True)
check('missing terminal key',solve({'a':{'b':{}}},['a','b'],'c'),False)
check('missing intermediate',solve({'a':{}},['a','b'],'c'),False)
check('empty path',solve({'c':1},[],'c'),True)
check('falsey terminal value',solve({'a':{'b':{'c':False}}},['a','b'],'c'),True)
check('nonmapping intermediate',solve({'a':N},['a'],'c'),False)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
depth three	`False`	`True`	Failed
missing terminal key	`False`	`False`	Passed
missing intermediate	`False`	`False`	Passed
empty path	`True`	`True`	Passed
falsey terminal value	`False`	`True`	Failed
nonmapping intermediate	`False`	`False`	Passed

SHA-256 / 72a47abe4fc14757270300bfbd307776dcaebcd2381b10fa8eba4dd45b5e7ade

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(obj, path, required):
    return bool(path) and path[0] in obj and isinstance(obj[path[0]],dict) and required in obj[path[0]]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('depth three',solve({'a':{'b':{'c':N}}},['a','b'],'c'),True)
check('missing terminal key',solve({'a':{'b':{}}},['a','b'],'c'),False)
check('missing intermediate',solve({'a':{}},['a','b'],'c'),False)
check('empty path',solve({'c':1},[],'c'),True)
check('falsey terminal value',solve({'a':{'b':{'c':False}}},['a','b'],'c'),True)
check('nonmapping intermediate',solve({'a':N},['a'],'c'),False)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
depth three	`False`	`True`	Failed
missing terminal key	`False`	`False`	Passed
missing intermediate	`False`	`False`	Passed
empty path	`False`	`True`	Failed
falsey terminal value	`False`	`True`	Failed
nonmapping intermediate	`False`	`False`	Passed

SHA-256 / 2356bc921f6a99622ba46333388c0deeaad38f03e6a0d96ce1e5bbf46aece9aa

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 6 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

Self-contained toy JSON-like schema contract over in-memory Python values; no compatibility with a production schema standard or callable binding is claimed. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-30T16:48:28.524600+00:00.

Case digest / bbddb53d58feec18b4e1c16e00ee19f62a2edcbdcdefe3888cefcd35fa37716e