Schema: reusable prompts and output contracts

[rajanbor]

Goal

Define library/schemas/prompt.schema.json for versioned project prompts that can be rendered and evaluated consistently.

Human contract

Document purpose, input variables, context requirements, output contract, constraints, examples, failure behavior, model assumptions, and eval references. Keep prompt text readable as Markdown.

Machine contract

Validate stable prompt ID/version, typed variables, required context, output schema reference, model capability requirements, token ceiling, and linked eval IDs. Secrets must never be valid defaults.

Acceptance criteria

• Schema, guide, valid prompt example, and invalid fixtures exist.
• Missing variables and incompatible outputs fail before model invocation.
• Prompt/eval references are validated.
• Version changes document compatibility impact.
• Rendered prompts are deterministic for identical inputs.

Depends on the document envelope; coordinates with eval and token-budget schemas.