Visual Excellence Skill

Use this skill when an AI agent is asked to make a KiCad schematic look professional — clean, readable, and conventionally drawn — not just electrically correct. It closes the loop between measuring cosmetic quality, applying safe fixes, and visually confirming the result.

This skill is specific to oaslananka/kicad-mcp-pro and should be kept synchronized with docs/tools-reference.generated.md.

When to use

• Post-capture cleanup before layout or review
• Preparing a schematic for a datasheet, report, or customer hand-off
• Whenever a sheet "works but looks rushed": off-grid parts, diagonal wires, colliding labels, sideways power symbols, inconsistent fonts

Do not use this skill to claim electrical correctness. Cosmetic fixes never substitute for ERC, connectivity review, or human engineering approval. Run sch_visual_qa / run_erc separately for correctness.

The invariant you can rely on

Every cosmetic fixer treats electrical connectivity as a hard invariant. It computes a coordinate-independent connectivity signature before and after the change; a fixer that would alter any net is refused on apply and never writes. So you can apply fixes without fear of silently breaking a net — but always confirm with the render and the visual diff, and finish with an ERC pass.

Required context

• Active project path and the schematic file(s)
• The target cosmetic score (default: 80/100)
• Whether you are allowed to modify the schematic (this skill mutates on apply=true; it needs write operating mode)

Primary MCP tools

Measure

• sch_cosmetic_score — 0–100 score with a per-category penalty breakdown and the worst_category to fix first (grid, wiring, typography, orientation, layout_balance, readability, documentation)
• sch_visual_qa — readability findings (overlaps, off-sheet, dense fanout)

Fix (dry-run by default; pass apply=true to commit)

• sch_align_to_grid — snap off-grid symbols, labels, wires, junctions
• sch_straighten_wires — flatten almost-orthogonal wire segments
• sch_resolve_label_overlaps — flip label justify so text stops colliding
• sch_normalize_power_orientation — upright sideways power/ground symbols
• sch_normalize_text_sizes — normalise outlier fonts onto the dominant size

See and verify

• sch_render_png — render the sheet so you can visually evaluate it
• sch_render_visual_diff — the exact before/after pixel delta of your last mutation, plus the list of changed objects
• run_erc — the electrical safety net after cosmetic edits

The loop

Run this loop per sheet until the score meets the target or no fixer applies:

1. Measure. Call sch_cosmetic_score. If cosmetic_score ≥ target, stop — the sheet is clean. Otherwise read worst_category.
2. Plan (dry run). Call the fixer matching worst_category with the default apply=false. Read connectivity_preserved and the changes list.
   • grid → sch_align_to_grid
   • wiring → sch_straighten_wires
   • readability (label overlaps) → sch_resolve_label_overlaps
   • orientation → sch_normalize_power_orientation
   • typography → sch_normalize_text_sizes
3. Decide. If connectivity_preserved is false, do not apply — the fix would change a net. Report it and hand back to the human (or fix the underlying wiring first). If true, continue.
4. Apply. Call the same fixer with apply=true. A refused status means the invariant caught a connectivity change at commit time — treat it as step 3.
5. See. Call sch_render_png and evaluate the image against the rubric below. Call sch_render_visual_diff and confirm the red delta covers only the objects you intended to move.
6. Re-measure. Call sch_cosmetic_score again. Confirm the score rose and no new category regressed. Return to step 1.
7. Guard. After the loop, run run_erc to confirm the cosmetic pass left the design electrically intact.

Stop after a full pass where every applicable fixer reports no_change, even if the score is still below target — the remaining gap needs human layout judgment, not an automated fixer. Report what is left and why.

Rubric — what "professional" looks like

Compare the sheet you render against these two reference renders (both are the same three-resistor circuit):

• reference/professional.png — clean: parts aligned on a row, one horizontal wire, and readable IN / MID / OUT labels.
• reference/rushed.png — the same circuit drawn badly: the net labels collide into an unreadable blob, the wire runs diagonally, and the parts sit off-grid at uneven heights.

The rushed sheet is still electrically identical — this is exactly the class of defect that ERC passes and cosmetic review must catch. When you evaluate a sch_render_png, check for:

• Grid — parts and wires sit on a regular grid; nothing looks hand-nudged.
• Orthogonal wiring — wires run horizontally/vertically; no diagonals.
• Legible labels — net labels and reference designators do not overlap and read cleanly against nearby text.
• Conventional symbols — power up, ground down, no sideways power symbols.
• Consistent typography — one dominant font size across the sheet.
• Balanced composition — content spreads across the sheet rather than crowding one corner.
• Complete title block — title, revision, date, and company are filled in.

Judge the rendered image, not just the score: the score is a fast proxy, but the render is the ground truth for readability.

Guardrails

• Cosmetic ≠ correct. Never sign off electrical behavior from this skill.
• Prefer dry runs first; only apply once connectivity_preserved is true.
• If a fixer is refused, the underlying net topology needs a human — surface it, do not force it.
• End with run_erc; a clean cosmetic pass must also be a clean electrical one.