Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add rjmurillo/ai-agents/plugin install project-toolkitWrote 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/rjmurillo/ai-agents/api-doc-authoring)<a href="https://agentmods.dev/skills/rjmurillo/ai-agents/api-doc-authoring"><img src="https://agentmods.dev/badge/skills/rjmurillo/ai-agents/api-doc-authoring/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/rjmurillo/ai-agents/api-doc-authoring"><img src="https://agentmods.dev/badge/skills/rjmurillo/ai-agents/api-doc-authoring.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 | $0.00055 | $0.01708 |
| Opus 5.5 | $0.00022 | $0.00683 |
| Sonnet 5.5 | $0.00011 | $0.00342 |
| Haiku 4.5 | $0.00006 | $0.00171 |
Grade A, and why
api-doc-authoring 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 160 lines — stays where its author put it; the contents beside it link to each section on GitHub.
API Doc Authoring
Document the task developers are trying to complete, prove the examples run, and make failure recovery first-class.
API documentation is entered through a developer use case, not through the implementation's endpoint inventory. A tired developer should reach a working path and recover from common failures without reverse-engineering the API.
This skill owns how API documentation is structured and validated for use. It does not own claim checking, prose style, or API design:
| Concern | Owner | How this skill uses it |
|---|---|---|
| Behavioral and cross-document claims | doc-accuracy |
Runs through the existing lifecycle gates. No second accuracy gate here. |
| DRY, YAGNI, derived mutable facts | code-qualities-assessment |
Link to the canonical fact. Do not restate it in each example. |
| Voice, banned words, dashes | voice.md and universal.md |
Consumed as written. This skill adds no style guide. |
| API and schema design | the business-behavior-first design owner (#5411) | Describe the resulting contract. Never redefine it. |
| Capability graph | check_capability_graph.py (#5396) |
This skill's owns and depends-on metadata. doc-accuracy declares no capability block, so it is cited, not declared. |
Triggers
document this API, write the API guide, quickstart for this endpoint,
add examples to the API docs, document the error responses
When It Applies
Apply when a developer will call the API to finish a task and the docs are new, rewritten, or touched by an API contract change.
Skip the narrative when the artifact is a true reference listing, such as a generated schema page, or the API is trivial or internal with one obvious call. Write the reference, mark it as reference, and stop. Do not invent a use case to fill space.
Process
developer goal -> minimum working request -> expected response
-> common failures + remediation -> advanced options
-> execute examples, then doc-accuracy through the lifecycle
What ships with it
5 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.
- 4d ago First seen · 160 lines · 55 tokens per session scan A 1f0fef1a668d
api-doc-authoring is a skill published in the GitHub repository rjmurillo/ai-agents (48 stars, last pushed today), licensed MIT. It adds 55 tokens to every session and 1,708 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-10-14.
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