Always use the skill to retrieve the ***plain syntax rules — but only if you haven't done so yet.

Each functional spec must imply a maximum of 200 changed lines of code. If the requirement is too large, use the skill to split it into multiple smaller, independent specs. Do not include LOC estimates in the spec text.

Specs are rendered incrementally, top to bottom. The renderer has no knowledge of future specs — only previously rendered specs are in context. This means:

Write in terms of behavior, concepts, and domain logic — not implementation constructs. Avoid language-specific types, generics syntax, framework annotations, or other constructs tied to a particular language or framework. General technical terms (null values, JSON types, HTTP status codes) are fine. Language-specific guidance belongs in .

The new spec must not contradict any existing functional spec. Conflicting specs are the most costly outcome. Before adding, review all existing specs and verify the new one is compatible. Use to check the new spec against every existing spec in one batched call — it lists every conflicting pair, so a pair-by-pair analyzer is not needed. If ambiguity exists, add explicit detail to eliminate any conflicting interpretation. For each conflicting pair the batched analyzer reports, use the skill to diagnose and fix it before proceeding.

Each functional spec must be unambiguous — the renderer should have only one reasonable interpretation. If a single line is not enough to fully disambiguate the behavior, use nested sub-bullets to add detail. Nested lines clarify the parent spec; they do not introduce separate functionality. Even with nested detail, the spec must still imply ≤ 200 LOC.

- :User: should be able to send a :Message: to a :Conversation:.
  - A :Message: must have non-empty content.
  - The :Message: is appended to the end of the :Conversation:.
  - All :Participant: members of the :Conversation: can see the new :Message:.

Specs must be detailed enough that a developer can use the built software without reading the generated code. All external interfaces must be explicit — REST endpoint paths and HTTP methods, CLI command names and arguments, file formats, message schemas, etc. Never leave interface details up to the renderer's discretion.

Functionality must be self-contained in the spec text. modules only import functional specs, so do not rely on implementation reqs to convey behavior — they won't be visible in downstream modules.

If the functional spec needs verification, use the skill to add acceptance tests after inserting the spec.