Revision Synthesizer Skill

Generates improved SKILL.md variants by synthesizing signals from grading failures, trigger rates, execution transcripts, and (optionally) human feedback. This agent is designed to be invoked 3 times in parallel with different strategy parameters to produce diverse candidates for the candidate-selector.

Variant Strategies

This skill must be invoked with a --variant parameter set to one of:

Variant A — Minimalist

Cut instructions, simplify, remove redundant steps. Reduce token count while maintaining or improving pass rate. The hypothesis: shorter skills reduce distraction and let the model focus on what matters.

Tactics:

• Remove verbose explanations and restatements of obvious facts
• Merge repeated verification steps into a single check
• Eliminate "optional" or "nice-to-have" sections that rarely affect output quality
• Replace multi-step sequences with single consolidated instructions where the model handles decomposition

Variant B — Additive

Add examples, edge case handling, clearer step descriptions, more detailed verification. The hypothesis: richer instructions produce more consistent output across diverse inputs.

Tactics:

• Add concrete examples for each instruction step (input → expected output)
• Add explicit edge case handling (e.g., "If the file is empty, return early with a warning")
• Expand verification steps with pass/fail criteria
• Add error recovery paths for common failure modes found in grading results

Variant C — Restructured

Reorganize instruction flow, change framing, use a different procedural structure. The hypothesis: the current structure causes the model to miss context or follow steps out of order.

Tactics:

• Reorder the workflow: put high-impact steps first, verification steps immediately after their relevant instructions
• Change framing: shift from imperative checklist to decision-tree or state-machine structure
• Group related steps under thematic sub-headings
• Move reference material to end (the model reads sequentially, so what it reads last has higher recency bias)

Workflow

Step 1: Gather All Signals

Read the following inputs:

1. Current SKILL.md: The full source skill file.
2. grading.json files: All pass/fail results from the output-grader, both with-skill and without-skill configurations.
3. Execution transcripts (if available): Full agent response texts from quality-evaluator outputs at evals/workspace/iteration-*/eval-*/{with_skill,without_skill}/outputs/response.txt.
4. Timing data: timing.json from each eval run.
5. Human feedback (if available): Any review notes or annotations from a human evaluator.

Step 2: Analyze Failure Patterns

From grading results, identify:

• Which assertions fail consistently (across multiple eval cases)?
• Do failures cluster around specific instruction types (e.g., output format instructions, verification steps)?
• Is the skill helping? Compare with-skill vs without-skill pass rates. If without-skill is higher on some assertions, the skill may be actively harmful for those cases.
• Do certain instructions produce over-constrained output that the assertion checker disagrees with?

Step 3: Generate Revision

Apply the variant strategy's tactics to produce a revised SKILL.md. Follow agentskills.io best practices:

• Generalize from feedback, don't narrow-patch: If "the chart lacks axis labels" fails, don't add "always add axis labels to charts." Instead, add a general instruction like "Verify all visual outputs include proper labels and units."
• Keep skill lean: Every instruction should have a demonstrable impact on at least one eval assertion. If an instruction never affects grading, consider removing it.
• Explain the why: Prefer reasoning-based instructions ("Check artifact completeness because partial outputs appear correct but lack required metadata") over arbitrary rules ("Always run step 3 before step 4").
• Bundle repeated work: If multiple steps require reading the same file, have them read it once and reference the result.

Step 4: Write Output

Write the complete revised SKILL.md to:

evals/workspace/revisions/revision-<variant>.md

This must be a complete valid SKILL.md, not a diff or a partial fragment. Include:

• Full YAML frontmatter with name and description
• Complete markdown body with all sections

The name field must match the original skill name (not the variant name). The description field may be updated if the trigger-aggregator or failure analysis suggests changes.

Step 5: Self-Validate

Before writing the final file, validate the revision:

skills-ref validate <output-path>

If validation fails, fix the issues and re-validate. Do not write an invalid SKILL.md. If the revision cannot be made valid after 3 attempts, write the best-effort version and annotate with a <!-- VALIDATION_FAILED: <reason> --> comment at the top of the file.

Step 6: Document Changes

Add a ## Revision Notes section at the bottom of the SKILL.md (or as a separate revision-<variant>-notes.md file) documenting:

• Which failures drove which changes
• Why the variant strategy was chosen for each change
• Expected impact on pass rate (qualitative prediction)
• Token count delta vs. original

Gotchas

• Explain WHY each change was made: The revision notes are as important as the revision itself. Downstream humans need to understand the rationale. "Removed step 4 because" is insufficient — explain what failure pattern step 4 was causing.
• Avoid adding instructions the model already knows: If the model consistently fails to "use kebab-case for filenames," adding "remember to use kebab-case" won't help. Instead, restructure the instruction to include a verification step: "After creating files, check that all filenames are in kebab-case."
• Removing instructions can be more effective than adding: If pass rates plateau despite additive changes, the skill may be too long, causing the model to skip instructions. The minimalist variant exists specifically to test this hypothesis.
• Output is a complete valid SKILL.md, not a diff: The candidate-selector reads the revision file directly as a skill source. Partial files or diff patches will break the pipeline.
• Validation must pass: An invalid SKILL.md will cause the candidate-selector to skip this variant with no partial credit. Validate before writing.
• Don't optimize the description alone: If the trigger-aggregator already optimized the description, don't undo that work. If the description needs further changes, justify them in revision notes and cross-reference the trigger-aggregator's optimized version.

Verification

Verify this skill produces correct output:

1. Create a fixture SKILL.md with known issues: verbose redundant steps, missing edge case handling, poor instruction ordering.
2. Create grading.json showing 3 assertion failures: one related to output format, one to missing verification, one to edge case handling.
3. Invoke revision-synthesizer with --variant B (Additive).
4. Confirm the output at evals/workspace/revisions/revision-B.md is a complete valid SKILL.md (runs skills-ref validate clean).
5. Confirm the output includes added examples, edge case handling, and more detailed verification steps.
6. Invoke revision-synthesizer with --variant A (Minimalist).
7. Confirm the minimalist revision is shorter (fewer lines or lower token count) than the original while still passing validation.
8. Confirm each revision includes ## Revision Notes documenting the rationale for changes.