Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/sd0xdev/sd0x-harness/best-practicesnpx skills add sd0xdev/sd0x-harness --skill best-practicesgit clone --depth 1 https://github.com/sd0xdev/sd0x-harnessWrote 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/sd0xdev/sd0x-harness/best-practices)<a href="https://agentmods.dev/skills/sd0xdev/sd0x-harness/best-practices"><img src="https://agentmods.dev/badge/skills/sd0xdev/sd0x-harness/best-practices.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 | $0.00101 | $0.02302 |
| Opus 5 | $0.00051 | $0.01151 |
| Sonnet 5 | $0.00020 | $0.00460 |
| Haiku 4.5 | $0.00010 | $0.00230 |
Grade A, and why
best-practices scanned grade A with 1 finding 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 today.
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.
Enumerates other installed skillslowAgent snooping
Other skills' SKILL.md files reveal prompts, capabilities and secrets that should be invisible to peers.
> **agent-browser detection**: Attempt `Skill("agent-browser", ...)` first. If error (not installed), fall through to Priority 2. Filesystem check (`ls .claude/skills/agent-browser`) is diagnostic only — may give false n Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.
How it starts
The opening of the file, as written. The whole thing — 196 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Best Practices Audit
Supplementary Agent
Dispatch performance dimension analysis:
Agent({
description: "Analyze performance-related best practices compliance",
subagent_type: "performance-optimizer",
prompt: Analyze codebase for performance best practices related to: <topic> Check for N+1 queries, memory leaks, blocking operations, and caching issues.
})
Non-Negotiable Rules (Normative Source)
SKILL.md is the normative source for these rules. Reference files elaborate but do not override.
| # | Rule | Violation = |
|---|---|---|
| 1 | Phase 0 Comprehension Gate: Before any Phase 1–4 investigative call, output the audit plan block (see command definition) | Audit invalid |
| 2 | Phase 3 must invoke /codex-brainstorm via Skill tool — a raw transport debate is invalid |
Audit invalid |
| 3 | Phase 4 must include Debate threadId (non-empty, from Phase 3 session) |
Report rejected |
| 4 | Phase 4 must include Debate Conclusion referencing specific Phase 3 rounds (not blank, not placeholder) |
Report rejected |
Trigger
- Keywords: best practices audit, industry standards check, compliance audit, benchmark compliance, practice alignment, standards verification
- User has a current target (repo/service/module) to audit against standards
- Intent is conformance judgment (OK/WARN/FAIL), not open-ended exploration
When NOT to Use
| Scenario | Alternative |
|---|---|
| Broad research / discovery / multi-source exploration | /deep-research |
| Pure code review | /codex-review-fast |
| Architecture design | /codex-architect |
| Security-only audit | /codex-security |
MECE boundary:
/best-practicesproduces a conformance judgment (verdict + gap + debate proof)./deep-researchproduces a discovery synthesis (claim registry + coverage matrix + score). "What are best approaches for X?" ->/deep-research. "Does our code follow best practices for X?" ->/best-practices.
What ships with it
2 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.
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.
- today Changed 08cb8f5ced33
- 5d ago First seen · 196 lines · 101 tokens per session scan A 2f492b5f632e
best-practices is a skill published in the GitHub repository sd0xdev/sd0x-harness (188 stars, last pushed today), licensed MIT. It adds 101 tokens to every session and 2,302 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 1 finding (enumerates other installed skills). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
cc10x-router
THE ONLY ENTRY POINT FOR CC10X. Activate this skill for build, debug, review, and plan requests. Use when the user asks to implement, fix, review, plan, test, refactor, or continue code work. Trigger keywords: build, implement, create, write, add, review, audit, debug, fix, error, bug, broken, plan, design, architect…
building
Implementation skill for writing production code with TDD. Covers the RED-GREEN-REFACTOR cycle, false-RED detection, vertical slicing, scope escalation, test process discipline, and code generation patterns. Loaded by component-builder and bug-investigator.
diff-driven-docs
Use when a BUILD phase completes, a commit is staged, or a PR is about to be created, and the diff has not yet been reflected in documentation. Also use when the user says "update docs", "sync docs", "document this", or asks whether documentation is up to date.
exploration
Two-mode exploration skill: (1) design dialogue — turn rough ideas into validated designs through collaborative interview before planning; (2) spike — throwaway code answering ONE design question, deleted or absorbed, never shipped. Router invokes mode via dispatch context.
codebase-design
Canonical deep-module vocabulary (module, interface, depth, seam, adapter, leverage, locality) for designing a module's shape — a lot of behaviour behind a small interface at a clean seam, testable through that interface. The single source of truth for these terms; other skills (architecture, codebase-hygiene…
memory-and-handoff
Two-mode skill: (1) session memory — load/persist durable workflow state under .cc10x/ (activeContext, patterns, progress) so context survives compaction; (2) handoff package — portable, secrets-redacted export for a coworker, different tool, or fresh non-cc10x session.