name: ntn-sdd-sync description: Use after any meaningful ntn-sim-core phase/group completion or contract change to determine which SDD, status, validation, README, and todo documents must be updated in the same change set.

NTN SDD Sync

Use this skill after a phase/group lands meaningful design or implementation changes, especially when status, validation gates, contracts, or prompt packs may have changed.

Required Read Order

Read these first:

1. agent-governance.md
2. sdd/ntn-sim-core-implementation-status.md
3. the active phase SDD
4. sdd/ntn-sim-core-validation-matrix.md
5. sdd/ntn-sim-core-acceptance-gates.md
6. README.md if the entry-point guidance may have changed
7. todo/README.md and the relevant phase/group prompt file if prompt sequencing is affected

Workflow

1. Identify what changed:
   • architecture meaning
   • phase status
   • validation gates
   • contracts
   • prompt sequencing
2. Determine which documents must be updated in the same change set.
3. Update the smallest correct authority surface; do not spray edits across every doc.
4. Re-check for contradictions after editing.

Default Sync Targets

Depending on scope, check whether these need updates:

1. the active phase SDD
2. sdd/ntn-sim-core-implementation-status.md
3. sdd/ntn-sim-core-validation-matrix.md
4. sdd/ntn-sim-core-platform-refactor-roadmap.md
5. README.md
6. todo/README.md
7. the phase/group prompt files under todo/

Do Not

1. Do not move historical notes back into active sdd/.
2. Do not let todo/ become more authoritative than SDDs.
3. Do not update README or prompt files without checking the canonical SDD first.
4. Do not leave phase completion claims only in conversation text; write them to the repo.

Output

Report:

1. which docs were updated
2. why each update was necessary
3. which docs were checked but intentionally left unchanged
4. whether any follow-up sync is still needed