Conciseness

The body is lean — symptom-to-code pairs with terse, purposeful comments ("Normalize email", "Caches auth.uid() result") and no concept explanations — but the ~20-line "Common Error Codes" tables duplicate content already in references/common-errors.md, and the "Query Returning Stale Data" snippets spend tokens without delivering the promised cache bypass. This is 'efficient with minor instances that could be trimmed' (anchor 4) rather than the every-token-earns-its-place level of 5.

Actionability

Most sections give copy-paste-ready guidance (pg_policies/pg_tables RLS inspection, signInWithPassword normalization, upsert with onConflict, EXPLAIN ANALYZE, supabase secrets set), but a few fixes are comment-only hints ("Use transaction mode, not session mode" pooling advice, "Only create one Supabase client per app") and the stale-data and '_health' check snippets are not executable as written. Minor gaps place it at anchor 4, below the fully-executable 5.

Workflow Clarity

The "Quick Diagnosis" symptom-to-cause table provides a coherent triage entry point, and sections embed their own checks ("Test policy with your user ID", logging subscription status, inspecting seq_scan counts). It stays below 5 because there is no explicit verify-the-fix step (e.g., re-run the failing query after applying the fix), and above 3 because checkpoints are largely embedded rather than absent. No destructive/batch-operation cap applies since the guidance is predominantly read-only diagnostics.

Progressive Disclosure

The single reference (references/common-errors.md) is real, one level deep, and clearly signaled at the end of the body with a description of its purpose. However, the inline "Common Error Codes" tables duplicate the reference file's coverage, so content splitting is only mostly appropriate — anchor 4 ('good structure; minor organization gaps') rather than 5's fully appropriate split.

Specificity

Names the domain and four concrete issue areas ("auth errors, RLS policies, connection problems, and performance"), matching the 'several specific actions; minor gaps in coverage' anchor. It falls short of 5 because it rests on a single action verb ('Troubleshoot') and omits storage, realtime, and edge-function coverage present in the body.

Completeness

It explicitly answers both questions: the 'what' ("Troubleshoot common Supabase issues including auth errors, RLS policies, connection problems, and performance") and the 'when' with a concrete 'Use when...' trigger clause ("debugging Supabase issues, fixing errors, or optimizing performance"), mirroring the anchor-5 example pattern. It is not 4 because the 'when' clause is already explicit and specific rather than improvable.

Trigger Term Quality

"Use when debugging Supabase issues, fixing errors, or optimizing performance" plus "RLS policies" and "connection problems" give good natural-keyword coverage. Common variations users would actually say ("Supabase slow", "can't connect to Supabase", "Supabase not working") are missing, so it fits anchor 4 rather than the comprehensive synonym coverage of 5.

Distinctiveness Conflict Risk

"Supabase" defines a clear niche and every capability and trigger is Supabase-scoped, so it would not fire for unrelated skills — matching the 'clear niche with distinct triggers; minimal conflict risk' anchor. Not below 5 since no generic, cross-skill trigger terms appear.