Borrowing it
Nothing to install: this file belongs to diillson/chatcli. 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/diillson/chatcli/main/.agent/skills/powershell-windows/SKILL.mdgit clone --depth 1 https://github.com/diillson/chatcliWrote 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/diillson/chatcli/powershell-windows)<a href="https://agentmods.dev/skills/diillson/chatcli/powershell-windows"><img src="https://agentmods.dev/badge/skills/diillson/chatcli/powershell-windows/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/diillson/chatcli/powershell-windows"><img src="https://agentmods.dev/badge/skills/diillson/chatcli/powershell-windows.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 | $0.00019 | $0.00977 |
| Opus 5.5 | $0.00008 | $0.00391 |
| Sonnet 5.5 | $0.00004 | $0.00195 |
| Haiku 4.5 | $0.00002 | $0.00098 |
Grade A, and why
powershell-windows 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.
This is a copy
86% identical to powershell-windows — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 168 lines — stays where its author put it; the contents beside it link to each section on GitHub.
PowerShell Windows Patterns
Critical patterns and pitfalls for Windows PowerShell.
1. Operator Syntax Rules
CRITICAL: Parentheses Required
| ❌ Wrong | ✅ Correct |
|---|---|
if (Test-Path "a" -or Test-Path "b") |
if ((Test-Path "a") -or (Test-Path "b")) |
if (Get-Item $x -and $y -eq 5) |
if ((Get-Item $x) -and ($y -eq 5)) |
Rule: Each cmdlet call MUST be in parentheses when using logical operators.
2. Unicode/Emoji Restriction
CRITICAL: No Unicode in Scripts
| Purpose | ❌ Don't Use | ✅ Use |
|---|---|---|
| Success | ✅ ✓ | [OK] [+] |
| Error | ❌ ✗ 🔴 | [!] [X] |
| Warning | ⚠️ 🟡 | [*] [WARN] |
| Info | ℹ️ 🔵 | [i] [INFO] |
| Progress | ⏳ | [...] |
Rule: Use ASCII characters only in PowerShell scripts.
3. Null Check Patterns
Always Check Before Access
| ❌ Wrong | ✅ Correct |
|---|---|
$array.Count -gt 0 |
$array -and $array.Count -gt 0 |
$text.Length |
if ($text) { $text.Length } |
4. String Interpolation
Complex Expressions
| ❌ Wrong | ✅ Correct |
|---|---|
"Value: $($obj.prop.sub)" |
Store in variable first |
Pattern:
$value = $obj.prop.sub
Write-Output "Value: $value"
5. Error Handling
ErrorActionPreference
| Value | Use |
|---|---|
| Stop | Development (fail fast) |
| Continue | Production scripts |
| SilentlyContinue | When errors expected |
Try/Catch Pattern
- Don't return inside try block
- Use finally for cleanup
- Return after try/catch
6. File Paths
Windows Path Rules
| Pattern | Use |
|---|---|
| Literal path | C:\Users\User\file.txt |
| Variable path | Join-Path $env:USERPROFILE "file.txt" |
| Relative | Join-Path $ScriptDir "data" |
Rule: Use Join-Path for cross-platform safety.
7. Array Operations
Correct Patterns
| Operation | Syntax |
|---|---|
| Empty array | $array = @() |
| Add item | $array += $item |
| ArrayList add | `$list.Add($item) |
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 · 168 lines · 19 tokens per session scan A e902ee8d16b3
powershell-windows is a skill published in the GitHub repository diillson/chatcli (93 stars, last pushed today), licensed Apache-2.0. It adds 19 tokens to every session and 977 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 86% identical to powershell-windows, differing in 8 lines, and is treated as a copy.
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