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 iampantherr/SecureContext --skill developer-performance-instinctsgit clone --depth 1 https://github.com/iampantherr/SecureContextWrote 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/iampantherr/securecontext/developer-performance-instincts)<a href="https://agentmods.dev/skills/iampantherr/securecontext/developer-performance-instincts"><img src="https://agentmods.dev/badge/skills/iampantherr/securecontext/developer-performance-instincts/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/iampantherr/securecontext/developer-performance-instincts"><img src="https://agentmods.dev/badge/skills/iampantherr/securecontext/developer-performance-instincts.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 | $0.00020 | $0.00500 |
| Opus 5 | $0.00010 | $0.00250 |
| Sonnet 5 | $0.00004 | $0.00100 |
| Haiku 4.5 | $0.00002 | $0.00050 |
Grade A, and why
developer-performance-instincts 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 yesterday.
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 INSTINCTS
(Extracted from roles.json deepPrompt for the developer role during the v0.19.0 role/skill split. Original content preserved verbatim. Edit freely; the mutator will propose improvements based on skill_runs telemetry once this skill is invoked by an agent.)
Measure First: Never guess at performance. Profile in production or with production-representative data. console.log timing and Chrome DevTools performance tab are enough to locate 80% of perf problems.
Big-O Awareness: Know the complexity of your data structures. Understand that O(n²) in a loop over user data is fine for 10 users and catastrophic at 10,000. O(n log n) sort before a comparison is almost always correct. O(n) linear scan through a hash set boundary is a bug.
Database Performance: Indexes are the highest-leverage performance tool. Understand query plans (EXPLAIN ANALYZE). Identify N+1s with query logging in development. Batch operations where possible. Connection pooling is not optional in production.
Caching: Cache at the layer closest to the consumer (HTTP cache headers, CDN, Redis, in-process). Every cache layer adds a staleness problem. Prefer idempotent, immutable URLs that can be cached forever (content-addressed assets) over cached mutable data.
Frontend Performance: Largest Contentful Paint and Time to Interactive are the user-facing metrics that matter. Lazy-load routes and heavy components. Prefer fewer, larger bundles over many small ones for most apps. Tree-shake aggressively. Never ship unused CSS.
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.
- yesterday First seen · 36 lines · 20 tokens per session scan A 3d3ca8bacefc
developer-performance-instincts is a skill published in the GitHub repository iampantherr/SecureContext (8 stars, last pushed 2d ago), licensed MIT. It adds 20 tokens to every session and 500 once invoked, about $0.0001 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 2026-09-08.
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