Name: viceroy
Rating: 72.8 (1 reviews)
Author: fastly

viceroy

Runs Fastly Compute WASM applications locally with Viceroy, specifically for Rust and Component Model projects. Use when starting a local Fastly Compute dev server with Viceroy, configuring fastly.toml for local backend overrides and store definitions, running Rust unit tests with cargo-nextest against the Compute runtime, debugging Compute apps locally, adapting core WASM modules to the Component Model, or troubleshooting local Compute testing issues (connection refused, missing backends, store config). For non-Rust Compute work or understanding the Compute API, prefer the fastlike skill instead — its source code is easier to understand as a Fastly Compute API reference.

Quality

89%

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Securityby

Passed

No findings from the security scan

Quality

Content

78%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

The content is a well-structured overview with executable quick-start commands, targeted gotchas, and a clean one-level reference table whose files all exist. The main weakness is the absence of explicit validation feedback loops and minor over-explanation in the intro.

Suggestions

Trim the introductory sentence that restates Viceroy's purpose; the description already conveys it, so the body can open directly with the gotchas or quick start.

Add a short validate/troubleshoot step after 'viceroy -C fastly.toml bin/main.wasm' (e.g., confirm the server responds on 127.0.0.1:7676, and on 'connection refused' check [local_server.backends] coverage) to close the workflow feedback loop.

Move or briefly inline one concrete cargo-nextest invocation in the quick start so the testing path is actionable without requiring the reference file.

Dimension	Reasoning	Score
Conciseness	The body is largely lean with tight gotchas and an executable quick start, but the opening line ('Viceroy is Fastly's official local testing environment... allowing you to develop and test WASM services locally') mildly restates what Viceroy is, a minor over-explanation that could be trimmed.	4 / 5
Actionability	The quick start gives copy-paste-ready commands (cargo install, fastly compute build, viceroy -C fastly.toml bin/main.wasm) and gotchas cite concrete config keys and port 7676, but deeper test/adapt detail is offloaded to references, leaving minor gaps inline.	4 / 5
Workflow Clarity	A clear install→build→serve sequence is present and gotchas act as troubleshooting checkpoints, but there is no explicit validate→fix→retry loop; acceptable for a non-destructive local dev-server context, so this sits just below anchor 5.	4 / 5
Progressive Disclosure	The SKILL.md body is an overview with a well-signaled References table pointing one level deep to four real files (serve/config/test/adapt), each with a 'Use when' column, matching the clear-overview anchor 5.	5 / 5
	Total	17 / 20 Passed

Description

100%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

The description is a strong, third-person statement that crisply defines a niche and gives concrete trigger phrases with an explicit boundary against a sibling skill. All four dimensions land at the top anchor.

Dimension	Reasoning	Score
Specificity	Lists six concrete enumerated actions (starting a local dev server, configuring fastly.toml backend overrides and store definitions, running cargo-nextest tests, debugging, adapting WASM to Component Model, troubleshooting) — comprehensive coverage matching the anchor 5 example.	5 / 5
Completeness	Explicitly answers 'what' (runs Fastly Compute WASM locally with Viceroy for Rust/Component Model) and 'when' via a concrete 'Use when' clause enumerating multiple trigger scenarios, hitting the anchor 5 bar.	5 / 5
Trigger Term Quality	Covers natural user vocabulary including the file extension fastly.toml, tool name cargo-nextest, and concrete symptom strings ('connection refused, missing backends, store config'), matching comprehensive coverage with synonyms and file extensions.	5 / 5
Distinctiveness Conflict Risk	Has a clear niche (Viceroy local runtime for Rust/Component Model) and explicitly reduces conflict risk by routing non-Rust Compute work to the fastlike skill, giving minimal overlap risk.	5 / 5
	Total	20 / 20 Passed

Validation

100%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository: fastly/fastly-agent-toolkit
Path: skills/viceroy/SKILL.md
Commit: 42a6070

Reviewed: 7 days ago

Table of Contents

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