Lab 3.2 – Dynamic Skill Router¶

Run in the browser with Google Colab or locally via Docker / VS Code.

Objective: Build a router that inspects the incoming request (or DFD features) and exposes only the skills needed for that request, then measure the benefit versus “always attach every tool.”

Learning Goals¶

Classify intent with a lightweight, auditable heuristic (rules first; optional LLM classifier later).
Select a skill subset per class.
Compare full-tool vs. routed-tool runs on token estimate, number of tools exposed, and outcome correctness.
Document routing rules so a security reviewer can audit them.

Routing classes (starter)¶

Class	When	Skills exposed
`syntax`	User asks only “is this DFD valid?”	`validate_dfd_syntax`
`structural`	Questions about paths / trust boundaries	`validate_dfd_syntax`, `check_trust_boundary_paths`
`policy`	Questions about controls / baselines	`match_security_controls`
`full`	“Evaluate this DFD for compliance”	All four skills

Starter Location¶

labs/03-skills/
├── src/
│   └── router.py
├── notebooks/
│   └── lab-3.2-skill-router.ipynb
└── tests/
    └── test_router.py

Step-by-Step¶

1. Implement `SkillRouter.classify(request) -> RouteClass`¶

Start with keyword / feature heuristics (presence of DFD JSON, words like “path”, “control”, “validate only”, …). Keep the function pure and unit-tested.

2. Implement `SkillRouter.select(route) -> list[Skill]`¶

3. Side-by-side comparison¶

For a fixed set of requests, record:

Tools exposed (count + names)
Estimated prompt tokens for tool declarations
Whether the correct skills ran
Final structured outcome

4. Optional hardening¶

Reject requests that try to force a high-privilege skill without the matching intent.
Log every routing decision for audit.

Success Criteria¶

Criterion	Target
Router returns a deterministic class for the sample requests	Yes
Routed runs expose fewer tools than the full set	Yes
Unit tests cover each route class	Yes
Notebook shows a clear comparison table	Yes

Submission¶

Notebook with comparison table + routing rule documentation (bullet list is enough).