testpoint-planner

Read runtime access before choosing between explicit-path MCP, a live bridge session, and native/headless CLI. Their availability is separate.

Testpoint planner

RAG: engineering memory by default — shared workflow. Consult measurement/DFT material for probe loading, coverage and fixture access, and DipTrace guidance when selecting the placement/connection workflow.

Plan only explicit MCP/DipTrace standalone-pad testpoints; reported coverage is not a fixture-access simulation. Use public tools/list for exact callable names and get_capabilities for document/configured feature availability.

Workflow

1. Call diptrace_status, get_capabilities, and get_document_info; require a PCB and freeze its SHA-256.
2. Use list_testpoints and review_testpoint_coverage for the exact net scope. Preserve excluded, sensitive, high-speed, RF, clock, reset, and user-locked nets.
3. Call find_testpoint_candidates with explicit side, probe diameter, clearance, grid, and candidates per net. Ask the operator when fixture-side access or sensitive-net policy is absent.
4. Stage add_testpoints(..., dry_run=true) in a transaction. Never commit from a request for a plan.
5. Inspect preview_transaction, then validate_transaction. When placement is authorized, commit with expected_sha256; retain authorization already given for the selected scope.
6. A testpoint's net assignment is logical membership, not proof of copper connection. Inspect pads/traces/vias around candidates, route required short stubs with route_connection, or verify the same-net pour after native refill. Re-run run_testability_review, run_drc, and run_connectivity_check. Revert only this session's failed changes with a current hash guard.
7. Emit ../shared/result.schema.json.

Quantitative boundaries

• candidates_per_net is 1 through 100; the free-grid search is bounded to 5,000 candidate points.
• The API defaults are probe diameter 1.0 mm, clearance 0.5 mm, and grid 2.54 mm. They are search parameters, not universal fixture rules; expose them and let the operator override them.
• Each transaction accepts at most 100 operations and 500 conservatively counted affected objects/elements; this can be fewer than 500 unique physical objects.
• All distances are millimetres regardless of root Units.

The actual bounds are enforced in service.py, capability_model.py, and write_limits.py.

Refusals

• Do not claim probe access, fixture mechanics, or fabrication clearance from the free-grid check.
• Do not add a point to an unresolved or sensitive net without explicit operator scope.
• Do not use raw XML or bypass locked objects.
• Do not report completed after a skipped DRC/connectivity check or stale SHA.

Candidate ranking is heuristic; committed object identity and post-checks are document evidence.