Borrowing it
Nothing to install: this file belongs to irahardianto/rugged-gemini. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/irahardianto/rugged-gemini/main/.gemini/skills/performance-optimization-principles/SKILL.mdgit clone --depth 1 https://github.com/irahardianto/rugged-geminiWrote 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/irahardianto/rugged-gemini/performance-optimization-principles)<a href="https://agentmods.dev/skills/irahardianto/rugged-gemini/performance-optimization-principles"><img src="https://agentmods.dev/badge/skills/irahardianto/rugged-gemini/performance-optimization-principles/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/irahardianto/rugged-gemini/performance-optimization-principles"><img src="https://agentmods.dev/badge/skills/irahardianto/rugged-gemini/performance-optimization-principles.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 | $0.00036 | $0.00477 |
| Opus 5.5 | $0.00014 | $0.00191 |
| Sonnet 5.5 | $0.00007 | $0.00095 |
| Haiku 4.5 | $0.00004 | $0.00048 |
Grade A, and why
performance-optimization-principles 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
Performance Optimization Principles
Measure First
- Profile to find actual bottleneck (don't guess)
- Find 20% of code consuming 80% of resources
- Optimize that specific bottleneck
- Measure again — verify with benchmarks
- Repeat only if still not meeting goals
Don't optimize: "fast enough," rarely executed, no measurable problem.
Data Structures
- Hash map: O(1) lookup, unordered
- Array: O(1) index, O(n) search, ordered
- Tree: O(log n) ops, sorted
- Set: O(1) membership, unique
Wrong choice = degradation: array for lookups (O(n) vs O(1)), list for sorted data (O(n log n) vs O(log n)).
Avoid Premature Abstraction
Costs: runtime (indirection, virtual dispatch), cognitive (layers), maintenance (ripple). Start concrete, abstract when pattern emerges. No "future flexibility" without evidence.
Techniques
- Caching: store expensive results, TTL, proper invalidation
- Lazy loading: compute/load on-demand
- Batching: N queries → 1 query, batch INSERTs, pipeline Redis
- Async I/O: don't block, concurrent I/O ops
- Connection pooling: see @.gemini/skills/resources-and-memory-management/SKILL.md
Checklist
- Measured performance problem (not guessed)?
- Profiled for actual bottleneck?
- Appropriate data structures for access pattern?
- Expensive ops cached with invalidation?
- Batch ops instead of N+1?
- Non-blocking I/O where appropriate?
- Measured improvement after optimization?
Related
- Resources @.gemini/skills/resources-and-memory-management/SKILL.md
- Concurrency Mandate GEMINI.md § Concurrency and Threading Mandate
- Concurrency Principles @.gemini/skills/concurrency-and-threading-principles/SKILL.md
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 · 55 lines · 36 tokens per session scan A 738ae8f77d43
performance-optimization-principles is a skill published in the GitHub repository irahardianto/rugged-gemini (5 stars, last pushed 5mo ago), licensed MIT. It adds 36 tokens to every session and 477 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 2026-09-03.
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