Ref - Up-To-Date Docs vs rubber-duck-tutor
Ref - Up-To-Date Docs is an MCP server published by ref-tools. Marketplaces we read that list it: 1 (Docker MCP Catalog). rubber-duck-tutor is a plugin bundle for AI coding tools published by LeeJuOh. Marketplaces we read that list it: 1 (Community GitHub marketplaces). As of our marketplace pass on 2026-10-29. This pair was picked by a reader, not by our comparison rule, so search engines are asked not to index the page.
Where each is published
| Marketplace |  Ref - Up-To-Date Docs | |
|---|---|---|
| Docker MCP Catalog | Listed Version: sha256:8b5fcfe3e4e1 Forks (GitHub): 71 Pulls (Docker Hub): 19 439 Stars (Docker Hub): 2 Stars (GitHub): 1 185 Not marked · First seen |
Not listed |
| Community marketplace leejuoh/claude-code-zero | Not listed | Listed Version: 3.1.3 Forks (GitHub): 4 Stars (GitHub): 53 Not marked · First seen |
Each figure is the marketplace's own and is never added up across marketplaces. A marketplace that publishes no figure shows none: no number is not zero.
The facts side by side
| Fact | Ref - Up-To-Date Docs | rubber-duck-tutor |
|---|---|---|
| Marketplaces that list it | 1 | 1 |
| Stars (GitHub) (differs) | 1 185 (better) | 53 (worse) |
| Pulls (Docker Hub) (differs) | 19 439 | No figure on Docker Hub |
| Forks (GitHub) (differs) | 71 (better) | 4 (worse) |
| Last release | Not published | Not published |
| Where it runs (differs) | On your machine (mcp/ref-tools-mcp) | Installs as a plugin bundle |
| Transport (differs) | stdio | Not stated |
| Tools it declares (differs) | 2 | Not published |
| Environment variables it asks for (differs) | 1, secrets among them: 1 | Not published |
| Hooks it runs (differs) | Not published | 9 |
| Parts of the bundle (differs) | Not a bundle | 8 |
| Licence | MIT | MIT |
| Repository (differs) | github.com/ref-tools/ref-tools-mcp | github.com/leejuoh/claude-code-zero |
| Changes in the last 7 days (differs) | 0 | 2 |
| First seen (differs) | 2026-10-11 | 2026-10-26 |
Lines where the two differ have a tinted background and bold values. Where the data itself says which value is better (more marketplaces, a larger figure of the same marketplace, a fresher release, a verified mark on a marketplace that lists both), the better one is also marked green with ▲ and the worse one red with ▼. Where it runs, the transport, the tools, the settings, hooks, the bundle's parts, the licence and the week's changes are marked only as different: more or fewer is not better in itself.
What each says it does
Ref - Up-To-Date Docs
Ref powerful search tool connets your coding tools with documentation context. It includes an up-to-date index of public documentation and it can ingest your private documentation (eg. GitHub repos, PDFs) as well.
rubber-duck-tutor
Rubber duck tutor that keeps you engaged across the whole AI-coding lifecycle — before you ask AI to build (/duck-prebuild), once code is written and before you ship (/duck-verify, /duck-review), and when orienting to unfamiliar code (/duck-orient), plus /duck for auto-detect. /coach is its teaching sibling, manual-invocation only: /coach <topic> explains and drills a concept, /coach <file> or a bare /coach right after generating code dissects it section by section (what/why-this-way/where-it-breaks), and /coach alone surfaces an unresolved gap from a past duck session and teaches it — resolved only once you pass the exercise, not by saying you understand. Ship-point hooks triage what you just pushed against six risk categories and target the riskiest change you didn't actually discuss, fall back to retrieving an unresolved gap from a past session, or demote to a non-blocking scoreboard after three ignored confrontations in a row. Confrontation telemetry (fired/answered/ignored) is queryable from /duck-orient
How to run each
Ref - Up-To-Date Docs As a local MCP server: Docker image
claude mcp add --env "REF_API_KEY=<YOUR_REF_API_KEY>" --transport stdio ref -- docker run -i --rm -e REF_API_KEY mcp/ref-tools-mcpRequires: REF_API_KEY (secret)
rubber-duck-tutor As a Claude Code plugin
/plugin marketplace add leejuoh/claude-code-zero
/plugin install rubber-duck-tutor@claude-code-zeroCommands built only from what the marketplaces declare; the full set for every client is on each card.
Tools each declares
The marketplaces of rubber-duck-tutor publish no list of tools, so we do not compare tools.
Settings each asks for
The marketplaces of rubber-duck-tutor publish no settings it asks for, so we do not compare settings.
What it can do: Ref - Up-To-Date Docs · What it can do: rubber-duck-tutor · Compare two other plugins
Data comes from the Docker MCP Catalog (desktop.docker.com/mcp/catalog) and Docker Hub. Data comes from public marketplace files in GitHub repositories of their authors. Figures come from our own regular passes over the marketplaces, last read on . We publish no contact details for plugin publishers.