Conciseness

The ~14-line body is dense with non-obvious, project-specific rules ("Nested `keepPriorOrder` lists still use `sameUnordered` in `same*`", "OpenAPI `x-coralogix-collection: set` on object arrays is the contract for Terraform Sets") and contains no padding or explanation of concepts Claude already knows. Every token earns its place, matching the lean-and-efficient anchor.

Actionability

The guidance names exact functions and helpers (`collectionConv`, `expandElements`, `flattenSet`), gives a near-copy-paste expression ("`modelTypeName` must be `model.GoName(schema)+\"Model\"`, same as SDK `camelize`"), and explicit prohibitions ("Do not pair set items with prior by slice index"). It falls between anchors 3 and 4 — noticeably above the midpoint — but is not fully executable since there is no code snippet, diff, or command showing the corrected `collectionConv` shape or how to re-run the check.

Workflow Clarity

The Trigger → Fix → Why structure is coherent and fixes are organized by failure mode, but the sets-of-objects bullet bundles five coordinated changes (converter, expand/flatten, diagnostics, ordering, golden fixture) into one unordered list, and verification is only implicit — re-running `tfgen check` after the fix is never stated as a checkpoint. This matches the anchor for sequence present but checkpoints missing or implicit; it is not 4 because no explicit validation step exists.

Progressive Disclosure

The skill is a self-contained under-50-line body with clear Trigger/Fix/Why sections and no bundle files exist, so none are needed. Per the simple-skill guidance, a flat, well-organized SKILL.md with no external references scores full marks here.

Specificity

The description names concrete actions and constraints — "Fix collectionConv and modelTypeName, not the generated files" — and identifies exact error codes ("RENDERER_SHAPE_UNSUPPORTED set of object", "RENDERER_OUTPUT_INVALID"). It falls short of anchor 5 because the fix mechanics detailed in the body (e.g., accepting model.Set, model.GoName(schema)+"Model") are omitted, leaving minor gaps in action coverage rather than comprehensive coverage.

Completeness

It explicitly answers both questions: when — "Use when tfgen check fails with RENDERER_SHAPE_UNSUPPORTED set of object, or RENDERER_OUTPUT_INVALID on a dotted OpenAPI component" — and what — "Fix collectionConv and modelTypeName, not the generated files". This matches the anchor for clear, concrete answers to both what and when.

Trigger Term Quality

"tfgen check fails", "RENDERER_SHAPE_UNSUPPORTED set of object", "RENDERER_OUTPUT_INVALID", and "notification_center.ConnectorConfigField" are exactly the strings a user would paste from a failing tfgen run, covering both failure modes with a concrete example. These are the natural trigger terms for this niche; there are no meaningful synonyms or variations missing at the description level.

Distinctiveness Conflict Risk

The description is scoped to a single internal tool (tfgen) with specific error codes and a named dotted component ("notification_center.ConnectorConfigField"), giving it a clear niche with distinct triggers and essentially no overlap risk with other skills.