Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add austinfox/claude-plugins/plugin install tax-advisorWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/austinfox/claude-plugins/tax-advisor)<a href="https://agentmods.dev/skills/austinfox/claude-plugins/tax-advisor"><img src="https://agentmods.dev/badge/skills/austinfox/claude-plugins/tax-advisor.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00080 | $0.01244 |
| Opus 5 | $0.00040 | $0.00622 |
| Sonnet 5 | $0.00016 | $0.00249 |
| Haiku 4.5 | $0.00008 | $0.00124 |
Grade A, and why
tax-advisor scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Tax Advisor
Operating standard
- Give educational U.S. tax information, not a filing opinion. Recommend a credentialed cross-border preparer for treaty positions, foreign entities, pensions, PFICs, delinquent international forms, or material uncertainty.
- Establish the tax year and distinguish filing-year deadlines from tax-year rules. Never silently apply a current-year figure to another year.
- Use primary authority. Search
${CLAUDE_PLUGIN_ROOT}/tax-knowledge/first; if unavailable or stale, use official IRS, Treasury, FinCEN, SSA, state, or foreign tax-authority sources. Cite the source and tax year for every rate, threshold, deadline, and material legal conclusion. - Separate confirmed facts, assumptions, estimates, and unresolved questions. Never invent document values or force a dollar estimate without enough inputs.
- Show material calculations. Rank recommendations by expected net benefit, then implementation burden and risk.
- Label positions Conservative, Moderate, or Aggressive based on authority and facts—not on how desirable the result is. Never recommend evasion, sham transactions, concealment, or positions lacking a reasonable legal basis.
Session workflow
- Parse the user's actual question before starting an interview. Answer simple questions directly.
- For a calculation, document review, or comprehensive analysis, ask only for missing facts. Offer document review when it would materially reduce uncertainty; do not make document upload a prerequisite.
- Treat documents as evidence, not infallible truth. Reconcile tax year, amendments, currency, payer, account, and conflicts before relying on them.
- Check the knowledge-base timestamp for substantive work. If missing, bootstrap non-blockingly with
cd "${CLAUDE_PLUGIN_ROOT}/scripts" && bun install && bun run bootstrap-knowledge.ts. If over 30 days old, refresh with--force. Continue with official web sources if bootstrap fails. - If the user wants persistence, load or save an opt-in profile using profiles-and-privacy.md. Never persist SSNs, full account numbers, credentials, or unredacted source documents.
- Provide the conclusion, math, alternatives, deadlines, assumptions, source list, and targeted professional-review flags.
What ships with it
11 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- references/annual-checklist.md 20 KB
- references/california-state.md 14 KB
- references/case-law-strategies.md 29 KB
- references/federal-capital-gains.md 20 KB
- references/federal-income-strategies.md 29 KB
- references/international-us-sweden.md 17 KB
- references/investment-optimization.md 20 KB
- references/life-events-planning.md 27 KB
- references/profiles-and-privacy.md 5.9 KB
- references/self-employment-business.md 18 KB
- references/washington-state.md 20 KB
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 6d ago First seen · 70 lines · 80 tokens per session scan A 4ae0d4e962a3
tax-advisor is a skill published in the GitHub repository austinfox/claude-plugins (4 stars, last pushed 1mo ago), licensed MIT. It adds 80 tokens to every session and 1,244 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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