76ecf0e49e
Phase 6: skill.New constructor satisfying the agent.Skill contract; instruction-only skills; ordered additive composition; skill/clock (injectable-clock time tools) and skill/calc (recursive-descent arithmetic evaluator) as ready-made examples with full test suites incl. an agent-loop round trip. ADR-0013; README skills section + matrix synced. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
1.8 KiB
1.8 KiB
ADR-0013: Skill model — additive instruction+tool bundles
Status: Accepted — 2026-06-10
Context
mort's "skills" are reusable capabilities (a prompt fragment plus tools) attached to different agents at runtime. majordomo needs the same shape without mort specifics: attachable to any agent, on demand, composing additively and predictably.
Decision
- The contract is the three-method
agent.Skillinterface (Name / Instructions / Tools). It lives in package agent — the consumer of the contract — so skill→agent and agent→skill never both happen (no import cycle, and third parties can satisfy it without importing package skill). - Package skill is the standard constructor:
skill.New(name, WithInstructions(...), WithTools(...)/WithToolbox(...)). Instruction-only skills (nil toolbox) are legal — agent treats Tools()==nil as "no tools". - Composition is additive and ordered: instructions append to the agent's system prompt in attachment order, separated by blank lines; skill tools join the merged toolset with the same loud duplicate-name policy as toolboxes (ADR-0012). No hooks, no resources, no lifecycle — none of mort's skills need them, and out-of-scope discipline says don't build for hypotheticals (they'd be an additive interface upgrade later).
- Two ready-made example skills ship as subpackages and double as the
pattern reference:
skill/clock(time awareness; injectable clock) andskill/calc(exact arithmetic via a hand-rolled recursive-descent evaluator — no eval, no dependencies).
Consequences
- A skill instance is reusable across agents simultaneously (it is read-only after construction).
- mort's skill registry maps onto plain values: build
*skill.Skills, attach per agent at invocation time.