deephaven-mcp: Skill for Claude Code

When to use this vs. cli-help-improve: use cli-help-accuracy for surgical correctness-only fixes when the help structure is already complete. Use cli-help-improve for a full review that may add missing sections, single-source the output schema, or reconcile all three surfaces.

Before doing anything

Load ref-cli-help-standards. --help and the agents manifest both render from the command's HelpSpec, so fixing the spec fixes both; docs/CLI.md is authored separately and must be reconciled by hand. Fixing an inaccuracy in the spec without the doc (or vice versa) reintroduces drift, so check and fix both together.

Verify every claim against the handler

For each command in scope, read the handler and confirm:

• Options and arguments — every documented flag/argument exists with the stated name, type, default, and effect; every actual option has a help=; show_default=True where there is a default. No documented flag is missing from the code, and no code flag is undocumented.
• Error codes — the error_codes= block lists exactly the error_codes the command can raise. Trace each CliError(code=...) in the handler and in any shared helper it calls (e.g. acquire_daemon raises daemon_startup_timeout / daemon_reuse_refused / daemon_not_running / daemon_registry_corrupt). No phantom codes; no missing ones.
• Exit codes — the documented numeric codes match reality. Every CliError exits 2 except ErrorCode.TOOL_RETURNED_ERROR, the sole code whose exit_code is 3; the exit code is carried by the ErrorCode, not a CliError parameter (there is no exit_code= argument).
• Output fields — every OutputField names a real key in the format_output(...) payload, with the correct type; the mode (object/list/text) matches what is printed. The OutputSpec constant is passed once, as the spec's output= field (single source — never two literals that can drift). Each field's help string must accurately describe the value vocabulary the code emits — apply ref-output-serialization-conventions.
• Examples — each example command is runnable and uses real flags/args; jq filters reference real output keys.
• Plain text — no double-backtick literals or :func:/:class: markup in any surfaced string.