realign available MCP functions

[Lei Jiang (lionelc)]

This PR re-maps the MCP functions used in agent-kit and only picks those really appearing in documentdb-mcp. So it's a clean-up PR.

[German Eichberger (xgerman)]

Skill review: documentdb-query-optimizer

Architecture cost: PASS · Antipatterns: #5 (no evals — info, safe to skip for a technical reference skill) · Description quality: PASS

Verification of the PR's core claim

I cross-checked every tool name this PR now uses against upstream microsoft/documentdb-mcp/tool_list.md (pushed 2026-06-09):

• ✅ Kept/correct: list_indexes, explain_operation, find_documents, get_statistics, current_ops, create_index, drop_index, sample_documents, list_databases — all exist.
• ✅ Removed: optimize_find_query, explain_aggregate_query, explain_find_query, explain_count_query, collection_stats, index_stats, get_db_info — none exist upstream. Correct to drop them.

The realignment is accurate. (Note: npm documentdb-mcp-server is currently unreachable — "No versions available" — so source of truth was the upstream repo.)

Token cost

Level	What loads	Tokens	% of 200k
L1 — always loaded	frontmatter every turn	121	0.06%
L2 — on invocation	SKILL.md body	2,277	1.14%
L3 — on demand	references (both, summed)	2,564	1.28%
Full load	everything	4,962	2.48%

SKILL.md is 278 lines (under the 500-line ceiling).

🔴 Blockers

• none — no reference frontmatter, no PR-introduced broken links, body within limits.

🟡 Improvements

• SKILL.md Step 2 (lines ~162–163): Stale leftover from the rename. It still tells the agent to extract indexes_stats (usage frequency) and collection_stats (doc count, avg size) "from the explain("executionStats") response." Those fields came from the old bundled optimize_find_query; raw explain_operation / .explain() does not return them — they now require a separate get_statistics call. Internally inconsistent with this PR's own change.
• SKILL.md "MCP Tools Available" table: current_ops (and create_index / drop_index) are management tools. The kit's mcp.json ships ENABLE_MANAGEMENT_TOOLS=false, so they are not available under the default profile. The table lists current_ops as plainly available with no gate note.
• Cross-skill (out of this PR's scope): skills/natural-language-querying/SKILL.md still references the non-existent get_db_info. The same cleanup applied here should extend there.

🟢 Strengths

• Central claim holds: every retained tool name verifies against upstream; every removed one is genuinely absent. Clean, correct realignment.
• Adding mongosh equivalents for each MCP tool is a real improvement — gives the skill a working path when MCP isn't connected or management tools are gated off.
• Short spine + on-demand references preserved; architecture cost stays ~1.1% on invocation.

Recommended next step

Fix the Step 2 stale collection_stats/indexes_stats reference (point it at get_statistics) and add a one-line management-gate note for current_ops, then ship.

_{🤖 Generated with skill-reviewer}