deephaven-mcp: Skill for Claude Code

Review like a senior engineer. Every finding must answer three questions in concrete terms: what is wrong, what is better, why the change is worth its cost. All topics are fair game — correctness, security, design, duplication, clarity, naming, structure, tests. Be conscious of suggestions that do not serve a purpose.

Review the changeset described in the prompt. Common forms:

If no changeset is specified, default to uncommitted changes.

Steps

1. Identify changed files: Run the appropriate git command above to get the full list of changed files. If the changeset touches an area you have not worked in, load ref-project-reference first for the module map — what each package owns and which types cross package boundaries.

2. Review each file based on its type:

   File type	Skill to apply
   .py	review-python-file
   CLI help-bearing files (cli/_commands/*.py, cli/_help.py, cli/_manifest.py, cli/_errors.py)	review-python-file plus cli-help-accuracy (the surfaced help, error-code registry, and output schema must match the code and docs/CLI.md)
   MCP tool signatures (mcp_systems_server/_tools/*.py) or tool-wrapping CLI commands (cli/_commands/*.py setting wraps_tool/wraps_tools)	review-python-file plus run uv run --extra test pytest tests/cli/test_tool_wrapper_drift.py -q and apply ref-cli-tool-wrapping — a changed tool signature must be reflected in its wrapper's flags / intentionally_unsupported, and vice versa
   .md, .rst	docs-accuracy
   Pydantic config (config/schema/*.py, config/tree.py), *.json5 examples under config-samples/ai/config/, docs/CONFIGURATION.md	ref-configuration-conventions
   docs/ENV.md	ref-configuration-conventions plus docs-accuracy — the canonical environment-variable inventory; verify every entry still matches its reader in the code
   .agents/skills/**/SKILL.md, AGENTS.md	skill-review plus run uv run pytest tests/agents/test_skills_catalog.py — it pins the frontmatter contract, the README row, and every section citation and canonical-implementation pointer across the catalog, none of which markdownlint checks
   .json, .json5, .yaml, .toml (config files outside the schemas above)	ref-markdown-documentation-standards for inline doc-block formatting; verify syntax + cross-reference with any matching Pydantic schema
   .sh, bin/*, .github/workflows/*.yml (shell scripts, CI)	Verify shellcheck-clean, set -euo pipefail for new scripts, idempotent, and that any failure mode produces a non-zero exit
   Other	Review for correctness and appropriateness — name the specific property being checked (e.g., "Dockerfile uses pinned base image", "lockfile changes match pyproject.toml") rather than gesturing

3. Cross-cutting review — assess the changeset as a whole:

   • Unrequested surface: List every new environment variable, config field, CLI flag, error code, output field, MCP tool, noun or verb, exit code, public export, config file kind — or any other user-visible contract — in the changeset, and name the requirement each traces to. A surface entailed by an approved change (a requested command's own flags and error codes) traces to that request and is in scope. Flag any that trace to none (AGENTS.md Scope discipline). A well-executed unrequested feature — typed, tested, documented, fully covered — passes every other check in this list, so this is the only one that catches it.
   • New environment variable: Scan the whole diff — any file, including tests and docs — for an os.environ read, a click envvar=, or a new variable name. Each one must be explicitly requested and must carry its docs/ENV.md entry in the same changeset. A JSON field plus ${env:VAR} templating is the default answer; a new variable is a product decision, not an implementation detail. Apply ref-configuration-conventions, plus cli-command-add's anti-patterns for CLI code.
   • Design consistency: Names, abstractions, and patterns introduced in one file match what siblings already use. Flag any new pattern that supersedes an existing one without also retiring the old one.
   • Code changes that stale a skill: A changeset that adds, renames, or moves a module, or changes a symbol a skill names as a canonical implementation, staled a skill even when no skill file is in the diff. Check ref-project-reference (the module map) and grep the catalog for the old path or symbol — grep -rn '<old-name>' .agents/ AGENTS.md. This is the case the per-file routing table cannot catch, because the skill file itself is unchanged.
   • DRY across files: Identify any block of substantive logic that appears in two or more changed files; either extract to a shared helper in this changeset or flag for follow-up.
   • Test coverage of new code paths: Every new branch, error path, and public function in the changeset has at least one test that exercises it. List by file any new code paths with zero test coverage.
   • Public-surface contract: Every new or modified __all__, __init__.py export, MCP tool registration, CLI command, error code, or config field has its corresponding test pinning the surface (per tests-improve step 1 for __init__.py; per mcp-tool-add step 4 for tool registration; per cli-command-add for CLI; per config-field-add for config).
   • Output-payload consistency across tools/CLI: When the changeset touches more than one producer of a shared field (e.g., a field appearing in both an MCP tool return and the matching CLI wrapper), the emitted string values must agree exactly. Apply ref-output-serialization-conventions.
   • ...or anything else at the changeset level that looks off — backward compatibility, dependency/lockfile drift, performance regressions, security exposure, documentation that no longer matches the code. This list is illustrative, not exhaustive; trust your judgment.