Trim SKILL.md from 791 to 684 lines (1.7.1)

[fedorov]

SKILL.md grew to 791 lines in 1.7.0 with the MCP section, reversing the reduction trend since v1.5.0 (862 → 773 → 750). The guidance refactor.md has been tracking is under 500 lines, with a Phase 2 target of ~600.

791 → 684 lines (−13.5%), 15 code blocks.

Nearly all relocation, not deletion

• The three "what's new in IDC vX" queries move to a new Version Tracking section in references/sql_patterns.md. SKILL.md keeps the part that prevents mistakes — use series_init_idc_version / series_revised_idc_version, never prior_versions_index — as a pointer.
• The repeated from idc_index import IDCClient / client = IDCClient() preamble is dropped from six examples and stated once in the Overview. This matches how sql_patterns.md is already written.
• The second filter-value-discovery query duplicated the BodyPartExamined idiom already at sql_patterns.md:38-43. The flat-dirTemplate and source_bucket_location="gcs" download variants are now prose beside the canonical example.
• The DICOMweb endpoint table, the citations_from_selection parameter list, and the downloaded-file-naming bullets are condensed to prose; the full endpoint details remain in references/dicomweb_guide.md.
• Deduplicated the two references/bigquery_guide.md pointers in "Advanced Queries with BigQuery".

Deliberately kept

The cloud storage bucket table stays inline. cloud_storage_guide.md:23-25 does carry it verbatim, so compressing it wouldn't lose anything from the skill as a whole — but the table carries the CC BY-NC distinction that the license workflow depends on, and the compressed wording dropped the idc-open-data-two head-scans bucket entirely.

~600 is not reachable without deleting content rather than relocating it. What remains in the largest sections is anti-footgun guidance (the two download-method signatures, the "takes filter kwargs, NOT a DataFrame" warning) and decision tables, not redundant examples. refactor.md records this rather than leaving the target looking silently missed.

Test docstrings

Five test docstrings referenced SKILL.md sections by number (§1, §2, …), which is opaque without the file open. They now name the section. One was stale: "§6 Batch Processing" — section 6 has been Advanced Queries with BigQuery since batch processing moved to use_cases.md in v1.6.0.

Testing

Run against idc-index 0.12.5 / idc-index-data 24.2.2 / pandas 3.0.5:

Suite	Result
tests/test_snippets.py	98 passed (5m31s)
tests/test_mcp_server.py	8 passed

The version guard (SKILL.md frontmatter ↔ check_version.py) passes at 1.7.1.

🤖 Generated with Claude Code