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 skills add 45ck/skill-harness --skill context-engineering-plannergit clone --depth 1 https://github.com/45ck/skill-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/45ck/skill-harness/context-engineering-planner)<a href="https://agentmods.dev/skills/45ck/skill-harness/context-engineering-planner"><img src="https://agentmods.dev/badge/skills/45ck/skill-harness/context-engineering-planner/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/45ck/skill-harness/context-engineering-planner"><img src="https://agentmods.dev/badge/skills/45ck/skill-harness/context-engineering-planner.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00030 | $0.00271 |
| Opus 5.5 | $0.00012 | $0.00108 |
| Sonnet 5.5 | $0.00006 | $0.00054 |
| Haiku 4.5 | $0.00003 | $0.00027 |
Grade A, and why
context-engineering-planner 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 1mo 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.
What it actually says
Context Engineering Planner
Use this skill when an agent workflow needs deliberate context design instead of a large undifferentiated prompt.
Plan
- Identify the decision the agent must make and the evidence it needs.
- Split context into durable source, transient working context, generated evidence, and memory candidates.
- Prefer repo files, issues, manifests, tests, traces, and docs over prose recollection.
- Define what may be retrieved automatically and what must be explicitly requested.
- Define what should be compressed, summarized, or excluded.
- Name stale-context risks and refresh checks.
Context Classes
source: canonical specs, code, issues, policies, manifestsevidence: tests, logs, screenshots, traces, evaluation resultsmemory: reusable lessons worth recording with the project memory mechanismworking: temporary notes used only for the current runexcluded: secrets, private data, raw traces, irrelevant history, stale generated output
Output
Workflow Goal
Required Source Context
Evidence Inputs
Retrieval Plan
Compression Plan
Memory Candidates
Exclusions
Refresh Checks
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.
- 1mo ago First seen · 37 lines · 30 tokens per session scan A e5f6eabccd72
context-engineering-planner is a skill published in the GitHub repository 45ck/skill-harness (15 stars, last pushed 4mo ago), licensed MIT. It adds 30 tokens to every session and 271 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-08-30.
Other skills, from other repositories
do-it-context
Use when project terms, relationships, or invariants drift between user language, docs, and implementation, or when stable project knowledge keeps being rediscovered or the user asks to document it.
Knowledge
Manage the LifeOS Knowledge Archive — a curated, typed graph of People, Companies, Ideas, and Research notes with typed related: links; search, add, harvest, develop, ingest, and graph-navigate. USE WHEN knowledge, knowledge base, search knowledge, what do we know about, archive, harvest, knowledge status, develop…
Migrate
Intakes external content, classifies chunks against LifeOS taxonomy, commits with provenance. Sources: .md/.txt, stdin, LifeOS dirs, CLAUDE.md/Cursor/OpenAI Custom Instructions, Obsidian/Notion/Apple Notes exports. MigrateScan classifies → routing table. MigrateApprove with…
ContextSearch
Find prior LifeOS work — sessions, ISAs, conversations — by topic or date phrase; searches the work registry, titles, dir names, ISA bodies, and conversation logs, ranked by relevance. USE WHEN context search, prior work, browse sessions, recall, remember, previous sessions, context recovery, what did we do, find…
Interview
Reads seven constitutional files (TELOS, DAIDENTITY, PRINCIPALIDENTITY, PROJECTS, system prompt, PRINCIPALTELOS, ARCHITECTURESUMMARY) via TelosFreshness, surfaces stalest items, drives contextual peer conversation. Routes to ContextCheckin; falls back to Phase0Setup on fresh install. ContextAudit surfaces TBD markers.…
Harvest
Mines a single piece of content (URL, YouTube, article, text, file) for anything useful to LifeOS, ranks the findings, then ingests the content into the Knowledge Archive. USE WHEN harvest, harvest this, harvest , harvest , harvest this video, harvest this article, /harvest, /ha, mine this for the system, anything…