query-optimization

A database query-tuning skill for understanding and improving slow queries. It covers join choices, index selection, query plans, runtime profiling, and optimizer settings.

In plain words
What is it for?
Use it to read EXPLAIN output, choose indexes, inspect profiling events, adjust optimizer settings, and investigate why a database query is slow.
Why use it?
It helps turn a vague performance problem into evidence from the database’s plan and execution measurements. It also supports a step-by-step diagnosis when the cause is unclear.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/chmonitor/chmonitor/query-optimization
Any agent
npx skills add chmonitor/chmonitor --skill query-optimization
Clone the repo
git clone --depth 1 https://github.com/chmonitor/chmonitor

Made for: Claude Code, Codex.

Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,054 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00044 $0.01054
Opus 5 $0.00022 $0.00527
Sonnet 5 $0.00009 $0.00211
Haiku 4.5 $0.00004 $0.00105

Measured 2d ago against content hash 3a56a7a3b43a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

query-optimization 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 2d 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.

.agents/skills/query-optimization/SKILL.md · 76 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Changes

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.

  1. 2d ago First seen · 76 lines · 44 tokens per session scan A 3a56a7a3b43a

Subscribe to this mod's changes

query-optimization is a skill published in the GitHub repository chmonitor/chmonitor (285 stars, last pushed 5d ago), licensed GPL-3.0. It adds 44 tokens to every session and 1,054 once invoked, about $0.0002 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 2026-08-30.