PlanetScale database skills
Skill, agent skill, by PlanetScale
Assessment
Worth reading even without PlanetScale for the habits: select the columns you need, add the index the query wants, and branch a schema change. Watch it; adopt the practices now.
2026-10-09
Strengths
- Schema changes as branches with deploy requests, reviewable and reversible
- Index-aware query writing: the agent explains which index a query uses and adds the missing one
- Habits that transfer to any MySQL or Postgres, not only PlanetScale
Limitations
- Built around PlanetScale's hosted platform and CLI
- Another vendor's conventions, such as no foreign keys by default, baked into the advice
PlanetScale's agent skill teaches a coding agent its database conventions: schema changes on branches that are merged through deploy requests, queries written with the index in mind, and the pscale CLI to drive both.[1] PlanetScale is a hosted MySQL-compatible platform with a Git-like branching model for schemas.
What it changes
Without guidance, an agent treats a database like code: write something that runs and move on. The skill's example turns a select-star over a status and a date into a column list with a composite index on those two fields, with an estimate of the difference at ten million rows, and it creates the table on a branch with a deploy request rather than against production.[2]
Why it matters outside PlanetScale
The habits are general. Treat schema changes as reviewable code. Never select everything. Know which index a query uses and add the one it wants. Those hold on any MySQL or Postgres and are worth writing into a project's agent instructions whether or not the platform is in use.
Things to know
- Its advice against foreign-key constraints is a PlanetScale scaling convention, not a universal rule.
History
- 2026-10-09: article written and published.
- 2026-10-09: entry created.
Comments
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