Conciseness

Almost every sentence is framework-specific knowledge Claude cannot know (auto-refresh rules, receipt semantics, tool-loading behavior), so there is no filler — but there is real fat: two near-duplicate 'Do' bullets on fail() vs bare Error, an overlapping 'Don't' about provider integrations/outputSchema, and long passages (receipt supersession, designSystem plumbing) that could be tightened or deferred. Anchor 3 ('mostly efficient but could be tightened') fits better than 4 because the redundancy is more than minor.

Actionability

Fully executable throughout: a copy-paste-ready defineAction example with imports, a concrete CLI invocation ('pnpm action log-meal --name "Salad" --calories 350'), a complete http-option table, executable hook imports, a worked WriteReceipt object, and a Troubleshooting section with concrete fixes. Covers the common cases the way the anchor-5 example does.

Workflow Clarity

Clear decision order ('existing action → extend/create a defineAction → custom route as last resort'), an explicit stop trigger before adding files under server/routes/api/, and real feedback loops (verified:false receipts force a reconciliation retry; NoWriteError triggers argument-correcting retry; 405/parse-failure diagnostics). It falls short of anchor 5 because the create-an-action flow is implicit in prose rather than an explicitly numbered sequence.

Progressive Disclosure

All three referenced files (references/action-fields.md, provider-apis.md, examples.md) exist, are one level deep, and are well signaled both inline ('examples in references/action-fields.md') and in a References section with per-file descriptions. Below anchor 5 because substantial detail (receipt supersession rules, designSystem context plumbing, MCP key-tool mechanics) is inlined in SKILL.md when the established references/action-fields.md pattern is the natural home for it.

Specificity

Names several concrete actions — 'create and run agent actions', 'adding an API integration', 'wiring up frontend data fetching' — with only minor coverage gaps (e.g., updating or troubleshooting existing actions). More than the 1–2 actions of anchor 3, but not the comprehensive coverage of anchor 5.

Completeness

Explicitly answers both: what ('How to create and run agent actions... the agent calls them as tools and frontend code calls them through client hooks') and when ('Use when creating a new action, adding an API integration, or wiring up frontend data fetching') with concrete trigger phrases. Matches the anchor-5 pattern; a weaker 'when' would only merit 4.

Trigger Term Quality

'Use when creating a new action, adding an API integration, or wiring up frontend data fetching' uses natural developer phrasings that a user would plausibly say. A few common synonyms are missing (e.g., 'tool', 'endpoint', 'API route', 'hook up data fetching'), which keeps it below anchor 5 but comfortably above anchor 3.

Distinctiveness Conflict Risk

'Agent actions' with its framework-specific framing is a mostly distinct niche, but 'adding an API integration' and 'wiring up frontend data fetching' are broad enough to overlap with adjacent provider-API or frontend skills. Anchor 4 fits; anchor 5 would require triggers with minimal overlap risk.