Replace the full-metadata <available_skills> system-prompt block with a
compact <skill_index> (names only) and an on-demand describe_skill tool
when skills.deferred_discovery: true (default: false / backward compat).
New modules:
- skills/catalog.py — SkillCatalog (immutable, searchable; select: has no
cap, keyword/prefix search caps at MAX_RESULTS=5)
- skills/describe.py — build_describe_skill_tool(catalog) closure;
build_skill_search_setup() wires SkillSearchSetup into both the
LangGraph agent factory (agent.py) and DeerFlowClient (client.py)
Changes:
- Skill @dataclass(frozen=True); allowed_tools/required_secrets list→tuple
- Skill First prompt line gated on skill_names (deferred vs legacy wording)
- get_skills_prompt_section: short-circuit storage on deferred path;
merge user_id (upstream) + skill_names (this PR) params
- describe_skill tool parameter named "name" (matches prompt wording)
- select: branch removes [:MAX_RESULTS] cap (exact request, not ranking)
- AGENTS.md: document deferred_discovery config field + new modules
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>