reader-lens

reader-lens is a skill for Claude Code from alphabravo-oss/guild. It costs 48 tokens per session (2,296 once invoked), scanned A, original, MIT.

A guide for deciding what a documentation page should discuss for a particular reader. It separates user-facing details from implementation details and adjusts the level of technical detail accordingly.

In plain words
What is it for?
It is for planning or reviewing documentation for users, operators, and developers.
Why use it?
It keeps pages focused on information the intended reader can use instead of exposing irrelevant internal details.

Skill for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the webster plugin — 11 skills, 6 agents shipped together

Install

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.

Claude Code
/plugin marketplace add alphabravo-oss/guild
Claude Code
/plugin install webster

Made for: Claude Code.

Or install webster, the plugin that ships this one along with the rest of its 11 skills, 6 agents.

Wrote 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.

agentmods badge for reader-lens

README.md
[![agentmods](https://agentmods.dev/badge/skills/alphabravo-oss/guild/reader-lens.svg)](https://agentmods.dev/skills/alphabravo-oss/guild/reader-lens)
Your own site
<a href="https://agentmods.dev/skills/alphabravo-oss/guild/reader-lens"><img src="https://agentmods.dev/badge/skills/alphabravo-oss/guild/reader-lens.svg" alt="Measured on agentmods" height="20"></a>
Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,296 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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 5.1 $0.00048 $0.02296
Opus 5 $0.00024 $0.01148
Sonnet 5 $0.00010 $0.00459
Haiku 4.5 $0.00005 $0.00230

Measured yesterday against content hash f2e62a955405, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

reader-lens 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 yesterday.

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.

plugins/webster/skills/reader-lens/SKILL.md · 189 lines

How it starts

The opening of the file, as written. The whole thing — 189 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Reader lens

audience used to buy one thing: a reading grade. That is not enough, and the gap is visible in the output. A page can describe a status enum in short words and pass at grade 9:

A deployment's status is the field everything else in the UI hangs off. This page is about how that field moves. It is also about the sub-phase field underneath it.

Nothing there is untrue, nothing is long-winded, and it is not documentation. It is a developer's model of the system handed to somebody who wanted to know whether their cluster was ready.

So the audience is a lens before it is a grade. It decides subject matter first and sentence length second.


The rule

A page may name only the things its reader can touch.

Audience May name May not name
user Screens, buttons, fields, menus, files they have, what the product gives back, what it says when something fails Symbols, routes, environment variables, architecture
operator All of the above, plus commands, flags, config files, environment variables, ports, logs Symbols and architecture
developer Anything in the system nothing

doctype.py check enforces this. On a page below developer it is a defect to name a symbol in backticks, a request route, or a part of the architecture, and on a user page an environment variable as well. A page that declares no reader is itself a defect: in the last full run of this plugin before the rule existed, not one of 67 pages declared an audience, so the lens never fired.

Writing from the screen

The reliable move is mechanical. Before writing a user page, get the words the product prints on itself. survey.py returns them under user_surface:

python3 ${CLAUDE_PLUGIN_ROOT}/scripts/survey.py . > .webster-survey.json
WEBSTER_SURVEY=.webster-survey.json \
  python3 ${CLAUDE_PLUGIN_ROOT}/scripts/doctype.py check docs

Save the survey and pass it. It is not an optional courtesy: it is the only oracle the lens has that lives outside the thing being judged. With it, the product's own screen and button names stop being reported as internal symbols, and an environment variable is one the code actually reads. Without it, whether PIONEER_API_URL on a user page is a leak depends on whether some other page in the same set happens to show it being assigned, which means adding a page changes the verdict on a different page and deleting one makes a defect disappear. The check says which oracle it used on every run.

Read the full file on GitHub · 189 lines

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. yesterday First seen · 189 lines · 48 tokens per session scan A f2e62a955405

Subscribe to this mod's changes

reader-lens is a skill published in the GitHub repository alphabravo-oss/guild (2 stars, last pushed 3d ago), licensed MIT. It adds 48 tokens to every session and 2,296 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 2026-09-04.

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