cell-spanning

Merge adjacent body cells with cellSpanningFeature: value-based rowSpan opt-in per column via spanRows, per-row colSpan via spanColumns, and the covered-cell convention where a span of 0 means skip the cell. Load for merged data grids, spans that disappear after sorting or paginating, ragged table rows, or a cell that unexpectedly merges down the whole tbody.

Quality

90%

Does it follow best practices?

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Securityby

Passed

No findings from the security scan

Quality

Content

88%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 tightly written, highly actionable feature skill with executable patterns and a strong wrong-vs-correct mistakes section. The only real gap is progressive disclosure: the inlined API surface and explanatory prose could be trimmed or moved to a reference file now that the body exceeds a quick-scan length.

Suggestions

Move the per-method API list and the longer Common Mistakes rationale (e.g. merge-aware selection internals, HTML rowspan='0' semantics) into a references/ file, keeping SKILL.md as a quick-start overview with one-level-deep links.

Tighten the prose around predicate anchoring and pinning clamps to the non-obvious rule only, trimming restated mechanics that the code already shows.

Consider adding a short 'Use when' recap line at the top of the body mirroring the description's triggers, so the file is self-describing without the frontmatter.

Dimension	Reasoning	Score
Conciseness	The body is efficient and assumes Claude knows TS/React, but explanatory prose (the HTML rowspan='0' semantics, predicate anchoring, merge-aware selection internals) adds tokens beyond the lean minimum, so it sits just below 'every token earns its place'.	4 / 5
Actionability	Fully executable, copy-paste-ready code covers setup, column opt-in, spanColumns, the skip-covered render loop, and disabling, while Common Mistakes pairs wrong-vs-correct snippets for the frequent failure modes.	5 / 5
Workflow Clarity	This is a single-purpose feature skill with an unambiguous usage path (Setup → opt columns → declare spans → render with skip loop → disable), and the simple-skill exception applies since it involves no destructive or batch operations requiring validation checkpoints.	5 / 5
Progressive Disclosure	Content is well-organized into Setup, Core Patterns, Common Mistakes, and API Discovery with no bundle files to offload into, but at ~146 lines and with the API surface inlined it is not the clean overview-plus-one-level-references ideal.	4 / 5
	Total	18 / 20 Passed

Description

92%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.

A strong, specific description that names concrete mechanisms and pairs a clear 'what' with an explicit 'when' trigger clause. Slightly jargon-forward in the lead, which keeps trigger-term coverage just shy of comprehensive.

Dimension	Reasoning	Score
Specificity	Lists multiple concrete mechanisms — 'value-based rowSpan opt-in per column via spanRows', 'per-row colSpan via spanColumns', and 'covered-cell convention where a span of 0 means skip the cell' — giving comprehensive coverage rather than vague claims.	5 / 5
Completeness	It explicitly answers what ('Merge adjacent body cells with cellSpanningFeature...') and when ('Load for merged data grids, spans that disappear after sorting or paginating, ragged table rows...') with concrete trigger phrases.	5 / 5
Trigger Term Quality	The 'Load for' clause surfaces natural debugging phrases like 'ragged table rows', 'spans that disappear after sorting or paginating', and 'a cell that unexpectedly merges down the whole tbody', but the lead is jargon-heavy and lacks file extensions or synonyms, keeping it just below comprehensive.	4 / 5
Distinctiveness Conflict Risk	It occupies a clear niche (TanStack table cell-spanning) with distinctive debugging triggers and requires core/table-features, so overlap with unrelated skills is minimal.	5 / 5
	Total	19 / 20 Passed

Validation

87%

Warnings & errors only

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

Validation — 14 / 16 Passed

Validation for skill structure

Criteria	Description	Result
metadata_version	'metadata.version' is missing	Warning
frontmatter_unknown_keys	Unknown frontmatter key(s) found; consider removing or moving to metadata	Warning

	Total	14 / 16 Passed

Repository: TanStack/table
Path: packages/table-core/skills/cell-spanning/SKILL.md
Commit: 21d713f

Reviewed: 4 hours ago

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