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/dawiddutoit/custom-claude/agent-developmentnpx skills add dawiddutoit/custom-claude --skill agent-developmentgit clone --depth 1 https://github.com/dawiddutoit/custom-claudeWrote 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/dawiddutoit/custom-claude/agent-development)<a href="https://agentmods.dev/skills/dawiddutoit/custom-claude/agent-development"><img src="https://agentmods.dev/badge/skills/dawiddutoit/custom-claude/agent-development.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 | $0.00080 | $0.02484 |
| Opus 5 | $0.00040 | $0.01242 |
| Sonnet 5 | $0.00016 | $0.00497 |
| Haiku 4.5 | $0.00008 | $0.00248 |
Grade A, and why
Agent Development 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 3d 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.
The source is not reproduced here
No licence file
A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.
What ships with it
6 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.
- 3d ago First seen · 416 lines · 80 tokens per session scan A ff3324078bbe
Agent Development is a skill published in the GitHub repository dawiddutoit/custom-claude (2 stars, last pushed 7mo ago), with no licence file. It adds 80 tokens to every session and 2,484 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.
Other skills, from other repositories
pre-edit-safety-gate
Prepare a safe, current, and maintainable code change before editing. Use before a cohesive code or workflow change to assess the request and existing structure, then choose a local change, reuse, extension, or necessary refactor with clear ownership. Do not use to block ordinary TDD or authorized refactors.
cloud-run-basics
Cloud Run expert guidance. Use when deploying services, running jobs, or managing worker pools for HTTP, scheduled tasks, or background processing.
plan-enterprise
Complete 8-phase enterprise software planning cycle for mission-critical systems.
phase-5-adr
Phase 5 — Architecture Decisions with ADR generation and validation.
validate-adr
Validate Architecture Decision Records against 11 enterprise rules before marking as Accepted.
gcp-cloud-run
Production-ready Cloud Run on GCP: containerized services, Cloud Run Functions, cold start optimization, Pub/Sub integration, Cloud SQL, Secret Manager, concurrency tuning. Covers sharp edges and gotchas.