FA-99776 / Tool call schema validation / Open access

Exclusive bound is applied without checking its schema mode · case 01

Exclusive bound is applied without checking its schema mode.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The boundary rule is selected by a discriminator, but validation applies one comparison to every branch.

THE FAILURE

The boundary rule is selected by a discriminator, but validation applies one comparison to every branch.

Unsuccessful approach: Always requiring value > bound handles exclusive mode but rejects equality in inclusive mode.

Case contract

A conditional numeric schema accepts value > bound in exclusive mode, value >= bound in inclusive mode, and rejects any other mode.

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(value, bound, mode):
    return value >= bound
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('exclusive above',solve(N+1,N,'exclusive'),True)
check('exclusive endpoint',solve(N,N,'exclusive'),False)
check('inclusive endpoint',solve(N,N,'inclusive'),True)
check('inclusive above',solve(N+1,N,'inclusive'),True)
check('below either bound',solve(N-1,N,'inclusive'),False)
check('unknown mode',solve(N+1,N,'other'),False)
check('exclusive fractional above',solve(N+0.5,N,'exclusive'),True)
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
exclusive above	`True`	`True`	Passed
exclusive endpoint	`True`	`False`	Failed
inclusive endpoint	`True`	`True`	Passed
inclusive above	`True`	`True`	Passed
below either bound	`False`	`False`	Passed
unknown mode	`True`	`False`	Failed
exclusive fractional above	`True`	`True`	Passed

SHA-256 / be5bd3ec1b411784ccbc613fb28ae53133491dd683db3b9bf5ce643b40aa7480

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(value, bound, mode):
    return value > bound
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('exclusive above',solve(N+1,N,'exclusive'),True)
check('exclusive endpoint',solve(N,N,'exclusive'),False)
check('inclusive endpoint',solve(N,N,'inclusive'),True)
check('inclusive above',solve(N+1,N,'inclusive'),True)
check('below either bound',solve(N-1,N,'inclusive'),False)
check('unknown mode',solve(N+1,N,'other'),False)
check('exclusive fractional above',solve(N+0.5,N,'exclusive'),True)
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
exclusive above	`True`	`True`	Passed
exclusive endpoint	`False`	`False`	Passed
inclusive endpoint	`False`	`True`	Failed
inclusive above	`True`	`True`	Passed
below either bound	`False`	`False`	Passed
unknown mode	`True`	`False`	Failed
exclusive fractional above	`True`	`True`	Passed

SHA-256 / 25f182068c981b37689caa82299d6b0a7b447bb3ead5a2af4876152007a87a5a

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 7 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 2026-09-30T16:48:28.064273+00:00.

Case digest / 122639412f377207cc20bbc6b294081b5d90a1f27475727a7a3ba2226a6ed5c6