Filing penalties and the estimated tax safe harbour

One command on the Penalties and safe harbours server, callable over MCP as get_compliance_capabilities. Every result carries the method it used, the rule pack it was pinned to, what is still missing and whether coverage was complete, for a licensed professional to review.

What it needs, and why

This command takes no arguments: it reports what the server covers. Which calculators taxagent-compliance exposes, what it will not compute, and the rule pack its figures are pinned to. Reading the registry before promising anything is the difference between a refusal and a plausible wrong answer.

Requests it answers

“Which penalties can this server compute?”
“Does it work out the interest on late tax?”

An agent with these skills loaded picks the command from phrasing like that, asks for whatever input is missing, and reports the figures with the method that produced them.

Run it

scripts/mcp_server.sh --server compliance

The same command is exposed by taxagent-compliance, so Claude, Claude Code, Codex, Cursor and any other MCP client can call it directly. Analysis only. No tool in this server places orders, modifies custodian records or files returns. This server holds no client data: every figure arrives in the call and nothing is stored. Results are estimates over those figures, not a return and not tax advice. Interest is never computed: the rate is set quarterly and compounds daily, so no rate is stored here.

Limits it inherits from taxagent-compliance

Interest. The underpayment rate is set quarterly and compounds daily, so no rate is stored here and these figures are penalties only.
Reasonable cause, first-time abatement and the fraud rate, any of which changes the result substantially.
Whether estimated payments were timely by quarter, as opposed to sufficient in total.

The server, its other 3 commands and what it deliberately leaves alone are on the Penalties and safe harbours page.