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agent-harness-fault-injection

Use when an agent workflow needs deterministic recovery evidence for sandbox, MCP/tool, worker, checkpoint, memory, or orchestration failures.

Quality

73%

Does it follow best practices?

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SecuritybySnyk

Passed

No findings from the security scan

Fix and improve this skill with Tessl

tessl review fix ./skills/antigravity-agent-harness-fault-injection/SKILL.md
SKILL.md
Quality
Evals
Security

Quality

Content

75%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A strong, dense methodology skill: every section carries specific, testable guidance (fault matrix, deterministic schedules, invariant gating, machine-readable evidence) with no padding explaining known concepts. Its weaknesses are minor — safety/inconclusive rules are restated several times, the overall procedure is never laid out as a single ordered list, and a couple of instructions (timeline normalization, harness wiring) stay one level more abstract than the rest.

DimensionReasoningScore

Conciseness

The body assumes Claude's competence throughout — it never explains what an MCP server, checkpoint, or sandbox is — and uses dense prescriptive tables instead of prose. However, the production-boundary rule is stated three times ("Do not use this skill against a production target, real user data, live credentials" / "Never delete real data, revoke real credentials" / "Do not include destructive commands, exploit payloads, credential material") and the inconclusive-on-missing-evidence rule appears four times, so minor trimming is possible.

4 / 5

Actionability

Concrete, actionable artifacts abound: an exact evidence-record field list ("run_id", monotonic "seq", "retry_remaining", "deadline_remaining_ms"), a complete JSON schedule example, a 7-row fault matrix naming injection boundaries and required observations, named join policies ("all_required", "best_effort", "compensate"), and defined verdicts. Minor gaps keep it below 5: no executable harness/wrapper snippet is provided and "compare the normalized timeline" leaves the normalization undefined.

4 / 5

Workflow Clarity

Validation is explicit and repeated ("Assert invariants after every recovery transition, not only at final output", "Run the same schedule twice and compare the normalized timeline", "Gate the verdict on invariants and remaining budget, not output text alone"), the safety preconditions form a numbered checklist, and Common Pitfalls supply problem/solution feedback loops. The end-to-end sequence is never enumerated as one ordered procedure — it must be assembled from the topic-ordered sections and the example run — which is the minor gap separating it from anchor 5.

4 / 5

Progressive Disclosure

No bundle files exist (no references/, scripts/, or assets/ directories) and the single SKILL.md is well-sectioned with scannable headers and tables; the content is cohesive methodology rather than bulk reference material that clearly belongs in a separate file. It sits at anchor 4 rather than 5 because there are no one-level-deep references at all, and sections like the evidence field specification could arguably be split out to slim the overview.

4 / 5

Total

16

/

20

Passed

Description

61%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

The description has a strong, explicit trigger clause with good domain keyword coverage and a reasonably distinct testing niche, but it is a 'when'-only description: the skill's actual actions (deterministic fault injection, invariant verification, verdict output) are never stated. Adding a leading 'what' statement would move completeness and specificity up a full level each.

Suggestions

Lead with an explicit third-person 'what' statement before the trigger clause, e.g., 'Injects deterministic, fixture-controlled faults (sandbox denials, tool timeouts, worker restarts, checkpoint loss) into a disposable agent-harness run and emits a fault matrix, event timeline, and recovery verdict.'

Add natural trigger terms users would actually say: 'fault injection', 'retry/timeout behavior', 'resilience or chaos testing of agent workflows', 'exactly-once effects', 'checkpoint recovery'.

Tie the broad scope words ('sandbox', 'memory', 'orchestration') more tightly to the testing context (e.g., 'failures in ... during a recovery test') so they cannot trigger for general sandbox-setup, memory-management, or orchestration-pattern requests.

DimensionReasoningScore

Specificity

The description names the domain and a concrete deliverable ("deterministic recovery evidence" for "sandbox, MCP/tool, worker, checkpoint, memory, or orchestration failures") but never states the actions the skill performs — fault injection, building a fault matrix, or emitting a verdict are all absent. It matches anchor 3 (domain plus an implied action, not comprehensive) rather than 4, which requires several explicit action verbs.

3 / 5

Completeness

The 'when' is explicit and specific ("Use when an agent workflow needs deterministic recovery evidence for..."), but the 'what' exists only implicitly inside the when-clause — no statement of what the skill does. Scoring only what is stated, this is richer than anchor 2's bare trigger ("Use when working with documents") but lacks the explicit 'what' that anchors 4-5 require, so it sits at 3.

3 / 5

Trigger Term Quality

Good natural keyword coverage for the domain: "agent workflow", "recovery", "sandbox", "MCP/tool", "worker", "checkpoint", "memory", "orchestration failures" are all phrases a harness developer would use. A few natural terms are missing — notably "fault injection" (the skill's own name), "retry", "timeout", and "resilience/chaos testing" — which fits anchor 4's 'good coverage, a few natural terms missing'.

4 / 5

Distinctiveness Conflict Risk

The recovery-evidence-testing framing ("deterministic recovery evidence", enumerated failure classes) carves a distinct niche unlikely to steal triggers from unrelated skills. Minor overlap risk remains: broad terms like "sandbox", "memory", and "orchestration" could also pull in sandbox-setup, memory-management, or multi-agent-orchestration skills when failure testing is not intended, matching anchor 4 rather than 5.

4 / 5

Total

14

/

20

Passed

Validation

93%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

Total

15

/

16

Passed

Repository

boisenoise/skills-collections

Path

skills/antigravity-agent-harness-fault-injection/SKILL.md

Reviewed

Table of Contents

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