Fskill Creator Migrate Agent Skill

fskill-creator-migrate

Goal

Analyze a large or hard-to-maintain legacy skill directory into structured migration context while preserving behavior. This sub-skill only performs migration pre-analysis and does not directly write final functional skill files; final artifact generation, runtime capability provisioning, file writing, and validation are handled by the main fskill-creator.

Invoked by the main skill when the user has an existing monolithic skill and wants to "refactor into functional", "migrate to functional skill", or "restructure into functions/references/scripts".

Principles

• Preserve existing behavior first, then optimize structure.
• Load the whole legacy skill package, not only SKILL.md.
• Keep source section and file evidence so reviewers can trace migrated content.
• Only output migration_context; must not directly write target skill files.
• Duplicated rules, schemas, and vocabulary move to reference_plan.
• Existing references/, scripts/, and tools/ are inventoried before proposing splits.
• Deterministic parsing, formatting, validation, or mechanical transforms are identified as script_plan, to be generated or preserved later by the main skill.
• Optional viewers only enter tool_plan; final files are generated uniformly by the main skill's add_runtime_capabilities.

References

| Resource | Load Timing | Purpose |

|---|---|---|

| shared_glossary | On demand | Stable migration terminology and output fields. |

| script_rules | Before proposing scripts | Rules for deciding what belongs in scripts/. |

External Inputs

| Field | Source | Description |

|---|---|---|

| legacy_skill_dir | user or repository | Path to the legacy skill directory containing SKILL.md. |

| legacy_skill_path | user or repository | Deprecated alias for legacy_skill_dir; may also be a direct path to SKILL.md, which resolves to its parent directory. |

| legacy_skill_content | user or repository | Existing skill markdown content when the directory is inaccessible. |

| migration_constraints | user | Constraints such as preserving file names, tone, or platform rules. |

| known_testcases | user or repository | Existing examples, traces, or expected behaviors. |

| existing_scripts | repository | Existing helper scripts associated with the legacy skill. |

| include_viewers | user | Whether to suggest generating tools/log_viewer.mjs and tools/tester_viewer.mjs. |

| script_runtime | environment | Whether this sub-skill's own Node.js scripts can be run. |

Execution Pipeline

| Step | Function | Purpose | Input | Output |

|---:|---|---|---|---|

| 1 | load_legacy_skill | Load and normalize the legacy skill package. | legacy_skill_dir<br>legacy_skill_path<br>legacy_skill_content | legacy_skill |

| 2 | map_existing_behavior | Identify goals, rules, inputs, outputs, and behaviors that must be preserved. | legacy_skill<br>migration_constraints | behavior_map |

| 3 | propose_function_split | Propose function boundaries, script opportunities, optional viewer tools, and target file layout. | legacy_skill<br>behavior_map<br>script_rules<br>include_viewers<br>script_runtime | migration_proposal<br>script_plan<br>tool_plan |

| 4 | extract_shared_references | Move duplicated or shared rules into references. | legacy_skill<br>migration_proposal<br>script_plan | reference_plan |

Output

The main skill combines the above outputs into:

| Field | Description |

|---|---|

| migration_context.legacy_skill | Loaded source skill package data. |

| migration_context.behavior_map | Behaviors that must be preserved. |

| migration_context.migration_proposal | Function split and target structure proposal. |

| migration_context.reference_plan | Terms, rules, and schemas that should go into shared references. |

| migration_context.script_plan | Deterministic helpers to generate, preserve, or refactor. |

| migration_context.tool_plan | Optional viewer choices. |

| migration_context.source_evidence | Legacy source sections, companion files, and behavior preservation evidence. |

Output Scope

Only output migration context; must not directly write target skill files or delete the legacy skill.