[skills-eval] dotnet-upgrade: 6 skills, 41% pass — 1 P0, 1 P1, 2 to strengthen, 2 keep

[AbhitejJohn]

🔄 EDITED 2026-07-19 — correction per #909

This finding has been revised. The errored trials that drove the FIX-RELIABILITY (P0) flag(s) below were shown in #909 to be judge-side infrastructure failures — a disabled/throttled PAT (CAPIError 400 organization disabled) and Vally's session.idle judge timeout — not fixture nondeterminism. Verdict scores already exclude errored trials, so re-running the classifier with those judge errors dropped reclassifies the affected skill(s):

Skill	Was	Now
migrate-nullable-references	FIX-RELIABILITY (P0)	STRENGTHEN

Struck-through text below is the superseded finding — in particular the "pin fixture SDK/tool versions" remediation does not apply. The title's P0 count has been updated. No eval re-run is required to correct the scores; recovering the lost judgments (optional) means re-judging those trials, not re-running the skill.

Context — cross-family skill evaluation: dotnet-upgrade

This issue is self-contained: it captures everything a skill author needs to act on the dotnet-upgrade plugin without opening the full report.

What this measures. Every runnable skill in dotnet/skills was run through Vally (0.7) on a cross-family matrix: 5 executor model families — opus-4.8, gpt-5.5, sonnet-4.6, haiku-4.5, mai-flash — each judged by a different family (judge ≠ executor; default judge = latest Opus, or GPT when Opus is the executor). For every skill, a skilled run is compared against a baseline (no-skill) run and scored per executor. This removes single-model and self-judging bias, so a skill that only helps one model family — or only its own family's judge — is visible.

• Data source: cross-family CI grid (run 29228914412 + backfills) — 5 executors × 85 runnable skills, 419 scored cells over 84 skills.
• Row grain: one row per skill, aggregated across its (up to 5) executor cells. avgN is the mean trial count behind the cells (trials 1–17; higher = more statistically trustworthy). thin-N flags directional-only rows.

dotnet-upgrade at a glance (portfolio scorecard)

Plugin	Skills	Cells	Pass	Impact	Tie-trials	Err	avg ΔTok	avg ΔTurns	avg ΔTools	Headline
dotnet-upgrade	6	29	41%	0.236	41	1	+400,544	+5.35	+6.21	🔴 Worst plugin: regressions + cost bomb

Insights. 6 skill(s); mean impact 0.24; 3/6 help ≥1 frontier model. No frontier-validated exemplar. Weak-model-only wins (frontier misses): migrate-dotnet10-to-dotnet11. Weakest: migrate-nullable-references (0.09).

Address first: migrate-dotnet9-to-dotnet10 — regression; migrate-nullable-references — reliability; dotnet-aot-compat — cost.

Address first: migrate-dotnet9-to-dotnet10 — regression; dotnet-aot-compat — cost. (migrate-nullable-references reclassified to STRENGTHEN — see EDIT above.)

How to read the table

Each skill is scored skilled vs. baseline on these axes:

Signal	Column	What it means	Good
Breadth	Families ✓ (n/5)	How many of the 5 model families the skill helps (per-family pass count, max 5/5)	4–5 / 5
Where	Passed on	Which families passed. Frontier = latest Opus + latest GPT are bold; Sonnet 4.6 / Haiku 4.5 / MAI Flash are mid/low-weight	frontier ✓
Magnitude	Impact (−1…+1)	How strongly the judge prefers skilled over baseline	≥ 0.4
Decisiveness	Ties▵	Trials where the judge saw no difference → skill is inert	low
Safety	Loss▵	Trials where skilled was WORSE than baseline → skill misfires	~0
Reliability	Err	Trials that errored/crashed in setup or judging	0
Efficiency	ΔTok / ΔTurns / ΔTools	Extra tokens / agent turns / tool calls vs baseline	≤ 0
Confidence	avgN	Mean trials behind the verdict; low N = directional only	≥ 3
Invocation	Call%	Share of skilled trials where the model actually invoked the skill	~100%

Families ✓ is cell-level (max 5/5); Ties▵/Loss▵ are trial-level tallies summed across all families (including the ones where the skill failed). A high Families ✓ next to non-zero Loss▵ is not a contradiction — see Passed on and the Action text for where losses landed.

Action buckets (each skill has one primary action; [flags] note secondary concerns):

Bucket	Priority	Meaning
FIX-RELIABILITY	🔴 P0	Errored trials / no verdict — stabilize the harness before trusting the score
FIX-DISCOVERY	🔴 P0	Model doesn't invoke it (Call% < 50%) — a triggering/description problem
FIX-REGRESSION	🔴 P0	Skilled is worse than baseline on many trials — the skill misfires
ADD-DECISIVENESS	🟠 P1	Called ~100% but ties dominate, ~0 impact — inert; needs sharper behavioral steps
TRIM-COST	🟠 P1	Passes but with heavy token/turn overhead — trim verbosity
EXEMPLAR	🟢 keep	Broad, strong, reliable win — use as a template
EFFICIENT-WIN	🟢 protect	Wins and cuts turns/tools — the ideal shape
KEEP-POLISH	🟢	Solid majority win; minor polish + more trials
STRENGTHEN	🟡 P2	Marginal/mixed lift — sharpen triggers & success criteria

Per-skill actions

Skill	Families ✓	Passed on (frontier bold)	Impact	Ties▵	Loss▵	Err	avgN	Call%	ΔTok	ΔTurns	ΔTools	Action
migrate-dotnet10-to-dotnet11	3/5	Sonnet, Haiku, MAI	0.38	6	10	0	10.6	82%	-58,353	-1.79	-3.71	EFFICIENT-WIN · ✅ Better and cheaper. Wins on Sonnet, Haiku, MAI while saving 1.79 turns, 3.71 tools, 58,353 tok. What's good: it adds value without bloat — the ideal shape. Protect the brevity; don't let it grow. ⚠️ But both frontier models miss and regress — this may only be helping mid/low-weight models. Treat as a weak-model win, not a universal one; check the frontier trajectories before templating. ([both-frontier-miss], [frontier-regressed], [efficient])
dotnet-aot-compat	2/4	GPT, Haiku	0.35	2	0	0	1	100%	+2,879,373	+42	+52.25	TRIM-COST · 🟠 Passes but heavy (+2,879,373 tok). Value is real; cost isn't justified. Trim: (1) cut redundant/whole-file reads — point to specific sections; (2) replace "explore everything" with a targeted checklist; (3) move deep reference material behind links instead of inlining it. ([frontier-miss], [costly], [thin-N])
migrate-dotnet8-to-dotnet9	2/5	Sonnet, Haiku	0.26	8	14	0	11.4	98%	-3,639	-1.42	-0.93	STRENGTHEN · 🟡 Marginal/mixed (passes 2/5 — Sonnet, Haiku). Diagnosis: misses both frontier models — likely assumes context they solve unaided. Try: (1) sharpen the trigger so it fires only where it wins; (2) add 1–2 opinionated, concrete steps that change behaviour; (3) add trials to separate signal from noise. If frontier models never benefit, scope it explicitly to weaker models or reconsider its value. ([both-frontier-miss], [frontier-regressed])
thread-abort-migration	3/5	GPT, Sonnet, Haiku	0.21	4	4	0	5	76%	+2,387	+0.24	+0.24	KEEP-POLISH · 🟢 Solid majority win on GPT, Sonnet, Haiku. Losses/ties are concentrated in the non-passing cells (Opus, MAI), not the 3 passing ones — the passes are clean. To firm up: (1) raise trials on Opus, MAI; (2) investigate why a frontier model (Opus) didn't pass — that's the highest-value gap; (3) minor wording polish only. ([frontier-miss])
migrate-dotnet9-to-dotnet10	1/5	Haiku	0.15	17	31	0	16	87%	-47,159	-1.96	-4.23	FIX-REGRESSION · 🔴 Regresses ~39% of trials (worse than baseline), losing on Opus, GPT, MAI. The skill is over-applying. Fixes: (1) add explicit stop-conditions ("do NOT act when…"); (2) narrow the trigger to the exact scenario it helps; (3) demote prescriptive edits to suggestions the agent can decline. Prioritise the frontier miss (Opus, GPT). ([both-frontier-miss], [frontier-regressed])
migrate-nullable-references	1/5	GPT	0.09	4	3	1	2.8	87%	+126,419	+2.37	+2.83	FIX-RELIABILITY · 🔴 1 errored trial(s) — verdict can't be trusted until setup is deterministic. This is an infra/harness fix, not a content one: (1) capture the failing trial's stderr; (2) pin tool/SDK versions in the fixture; (3) add a setup smoke-check before scoring. ([reliability], [frontier-miss], [frontier-regressed], [costly]) 🔄 EDIT (see #909): STRENGTHEN · 🟡 Marginal (1/5 — GPT), mostly ties and costly (+126k tok). The 1 errored trial was a judge-side session.idle timeout (haiku) — this is a content-strengthening problem, not a reliability/harness one. Sharpen the trigger; add opinionated steps. ([frontier-miss], [frontier-regressed], [costly])

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_{Generated from the cross-family Call-to-Action report (CALL-TO-ACTION.md §4–§5; companion IMPACT-ANALYSIS.md). Regenerate the underlying tables with node deep-metrics.mjs "$env:TEMP\cf-ci" agg-ci → node gen-cta-tables.mjs agg-ci. Numbers are directional where avgN is low; treat single-trial cells as hypotheses to confirm with more runs.}

[github-actions]

🎯 Issue Triage

Summary: This is an automated cross-family skill evaluation report for the dotnet-upgrade plugin, covering 6 skills across 5 model families. The plugin is the worst performer (41% pass rate, 0.236 mean impact, heavy overhead). Two P0 items need immediate attention: migrate-dotnet9-to-dotnet10 (FIX-REGRESSION) and migrate-nullable-references (FIX-RELIABILITY).

Type: task — evaluation-driven work tracking item

Assigned owners: @webreidi, @AbhitejJohn, @agocke directly assigned. Teams that could not be assigned: dotnet/compat (version-migration skills), dotnet/appmodel and dotnet/skills-upgrade-reviewers (thread-abort, aot-compat).

Confidence: High — issue maps clearly to dotnet-upgrade, type is unambiguous, owners are well-defined in CODEOWNERS.

Similar issues: None found — this appears to be the only open skills-eval issue for dotnet-upgrade.

Triage details

• Area mapping: Issue title and body reference dotnet-upgrade plugin; maps to area-upgrade.
• CODEOWNERS match: /plugins/dotnet-upgrade/skills/* — multiple owners per skill. The three version-migration skills are owned by dotnet/compat; others by agocke, dotnet/appmodel, dotnet/skills-upgrade-reviewers.
• Confidence rationale: Straightforward eval report with clear plugin scope and structured action buckets.
• Suggested next steps: Address P0s first — migrate-dotnet9-to-dotnet10 needs stop-conditions/narrow trigger; migrate-nullable-references needs harness stabilization. Then tackle dotnet-aot-compat TRIM-COST (P1).

Generated by Issue Triage for issue #901 · 94.5 AIC · ⊞ 28.5K · ◷

[AbhitejJohn]

Verifying fixes for this plugin's skills

To re-run the cross-family evaluation and confirm a change moves the pass rate, cherry-pick the dispatch workflow from #920 and dispatch it scoped to this plugin:

git fetch origin abhitejjohn-cross-family-eval-workflow
git cherry-pick 7c97b7346          # single commit in #920
git push origin HEAD

gh workflow run evaluation-run.yml --ref <your-branch> \
  -f plugins="dotnet-upgrade" \
  -f executors="opus,gpt,sonnet46,haiku,mai" -f runs=3

To verify a single skill faster, scope with skills (the skill directory name, e.g. one of the skills listed above):

gh workflow run evaluation-run.yml --ref <your-branch> \
  -f skills="<skill-dir>" -f executors="opus,gpt" -f runs=3

Each skill is run skilled-vs-baseline across the 5-family executor matrix, with the judge never in the executor's family (default judge = latest Opus; GPT when Opus executes). Results assemble into a cross-family pass matrix you can compare against the numbers in this issue. Full inputs/usage: #920.