Conciseness

The body is dense with non-obvious specifics Claude cannot be assumed to know ("At most 8192 items", "Reserved names: by_id and by_creation_time. Limits: 32 indexes per table, 16 fields per index", "Not v.bigint(), which is deprecated") and never pads with explanations of what Convex is. Every section is a compact table or code block where each token earns its place, matching the lean anchor-5 case.

Actionability

Code is complete and executable throughout: a full defineSchema skeleton, a working withIndex query showing equality-prefix-then-range, search/vector index declarations, and return validators including _id/_creationTime. The Common mistakes table pairs each error with a concrete fix, covering the common cases in copy-paste-ready form.

Workflow Clarity

The skill has a clear arc (when to use → skeleton → validators → optional/nullable → unions → indexes → relationships → mistakes → checklist) and validation checkpoints exist ("npx convex dev pushes without a schema validation error", the "v.optional, backfill, then require" migration pattern), so the database-operation cap does not apply. It is not anchor 5 because error recovery is distributed in tables and a checklist rather than an explicit validate→fix→retry loop.

Progressive Disclosure

No bundle reference files exist, and the body is well-organized with clear section headers, a discriminated-unions cross-reference, and a Docs section of external links — good structure with most content appropriately placed. At ~240 lines, the validator reference table and Common mistakes table could plausibly live in separate reference files, which keeps it below the anchor-5 ideal of well-signaled one-level-deep references.

Specificity

"Designs convex/schema.ts tables, validators, indexes, and relationships" lists four concrete, comprehensive actions covering the domain, matching the anchor-5 pattern of multiple specific actions with full coverage. The soft tail "keeps the schema honest as data evolves" is supplementary rather than a gap, so this is not the anchor-4 case of minor coverage gaps.

Completeness

The first sentence explicitly states what the skill does and the "Use when..." clause gives five concrete trigger scenarios, matching the anchor-5 exemplar structure. It is not anchor 4 because the when-clause is fully explicit rather than merely present-but-could-be-more-specific.

Trigger Term Quality

Triggers like "creating tables", "adding fields", "choosing index fields", "modeling relationships", and "a validator error appears at deploy time" are natural phrases users would say, giving good coverage. It falls short of anchor 5 because common variations such as "schema migration", "query", or "database" are absent.

Distinctiveness Conflict Risk

"convex/schema.ts", "validator", and "deploy time" pin the description to the Convex backend niche with distinct triggers and minimal conflict risk with other skills. No broader or generic language creates overlap with unrelated skills.