THE ARCHITECTURE
Like the Google Sheets add-on and Figma plugin, TranslateSheet MCP uses a remote server architecture with OAuth 2.1 authentication.
The MCP server is built with the official @modelcontextprotocol/sdk (TypeScript, v1.26+) and deployed on Cloud Run. It implements Streamable HTTP transport with SSE for bidirectional communication, OAuth 2.0 with PKCE (RFC 7636) for secure authentication, and RFC 7591 dynamic client registration so any MCP client can connect.
THE PLUGIN
The Claude Cowork plugin packages everything into a .zip that installs directly in Claude Desktop's Cowork tab. It includes:
.mcp.json -- MCP server configuration pointing to the remote Streamable HTTP endpoint
.claude-plugin/plugin.json -- Plugin metadata (name, version, icon, keywords)
skills/ -- Five contextual skill guides that Claude activates automatically based on what you're doing
SKILLS SYSTEM
The plugin ships with five domain-specific skills. Claude reads these automatically when a task matches, giving it expert-level knowledge about translation best practices:
translate -- Full parameter reference for translate_text including formality, context, custom instructions, glossaries, error handling, and best practices for large text
glossary -- Complete guide to listing, inspecting, creating, and applying glossaries. Covers multilingual glossaries, language pair rules and entry format
create-glossary -- Step-by-step guide for building glossaries from scratch: TSV format, naming conventions, entry writing tips, common glossary templates (brand, technical, medical, legal)
context -- When and how to use the context parameter for short/ambiguous texts like product names, UI labels, and headlines. Includes decision matrix for when context helps most
instructions -- Custom instructions reference for controlling tone, preserving terminology, targeting audiences, and enforcing style rules with examples by category
These skills mean Claude doesn't just call the tools -- it understands when to use glossaries vs. context vs. custom instructions, and how to combine them for maximum translation quality. :)
TOOLS (8 MCP TOOLS)
Tool
Description
translate_text
Translate text with optional glossary, formality, context, and up to 10 custom instructions
create_glossary
Create multilingual glossaries from term lists -- the only translation MCP with glossary creation
list_glossaries
List all glossaries with metadata (name, ID, language pairs, entry counts)
get_glossary_entries
Retrieve term mappings (source -> target) for a specific glossary and language pair
get_supported_languages
Discover all 30+ supported languages with regional variants
get_formality_languages
Check which languages support formal/informal tone control
get_glossary
Get detailed information about a specific glossary
get_usage
Check subscription status and translation quota
WHY CLAUDE COWORK MAKES THIS SPECIAL
Because Claude Cowork has full access to your local filesystem and can run multi-step workflows, the plugin unlocks things that a standalone MCP client can't do:
Build glossaries from local files -- Point Claude at a folder of product docs, marketing briefs, or legal contracts on your machine. It reads the files, extracts key terminology, and creates a glossary via create_glossary -- all in one conversation. "Create an EN-DE glossary from everything in /Documents/brand-guidelines/."
Translate entire directories -- "Translate all .md files in /content/en/ to German and French, save them to /content/de/ and /content/fr/." Claude reads each file, applies the right glossary, and writes the translated files back to disk with the folder structure preserved.
Localize codebases -- Point it at your i18n/en.json and say "Translate this to Japanese, Korean, and Spanish." Claude parses the JSON keys, translates the values (keeping interpolation variables like {{name}} untouched via custom instructions), and writes ja.json, ko.json, es.json.
Glossary from a PDF or spreadsheet -- Drop a terminology spreadsheet or brand guide PDF into a folder. "Build a glossary from brand-terms.csv." Claude reads the file, maps source/target columns, formats as TSV, and creates the glossary.
Batch translate with context -- Claude can read surrounding files to build context automatically. Translating a README? It reads the codebase to understand what the project does, then passes that as context for more accurate translation of technical descriptions.
Review and refine translations -- Translate a document, review the output side by side, then ask Claude to adjust: "The formality is too stiff for this audience, redo it with formality: less and add an instruction to use conversational tone." It rewrites the file in place.
Cross-reference glossaries -- "Check if my EN-DE glossary covers all the terms used in this marketing deck." Claude reads the document, lists all domain-specific terms, compares against get_glossary_entries, and suggests missing entries to add.
MORE IDEAS
Creates glossaries conversationally -- "Create a glossary from this product catalog" and the agent parses terms, builds TSV entries, and stores the glossary
Applies glossaries intelligently -- The agent decides which glossary to use based on the project, client, or content type
Combines all features -- Glossary + formality + context + custom instructions in a single call for maximum quality
Shares glossaries across platforms -- Same glossaries work in Figma, Google Sheets, and any MCP client