Lettras MCP server

• Registry nameorg.lettras/word-searchverified in the MCP registry

The registry name sits under lettras.org. The registry only lets a publisher use that namespace after proving control of the domain through DNS or HTTP.

• Stateanswerschecked 2026-10-22
• Tools8
• Server calls itselflettras
• Server version0.5.0
• Protocol version2025-06-18

On 2026-10-22 the server answered initialize and tools/list without a sign-in. First answer in 555 ms.

• Its tools do every use case we checked: generate printable word searches with a custom word list; create sudoku and crossword puzzles with your own clues.

Said by rules from the measurements above. The likely first call is a model's pick from the tool list; read its description before relying on it.

• INITE MCP score87 of 100answers 100 · does the job 100 · definitions 83 · context 100 · use 0 · connects 100
• What an agent can do with it2 of 2 use cases
• Answered100% of days13 of 13 daily checks
• Median first answer446 ms
• Space in an agent's context≈ 2,008 tokensthe definitions of all its tools (8), which an agent carries on every turn
• Tool definitionsB · 83 of 100
• Typed results0 of 8 toolsdeclared outputSchema: results come typed, read once

• Not saying whether it only reads or can destroy: 8 of 8

A program checks the server once a day: initialize and tools/list, no model. Tokens are the definitions' length at about four characters a token. The grade averages six checks of every tool's name, description, schema and annotations; it says how well the tools are described, not whether they work. The score weighs what was measured and nothing else: answering (25%), doing the product's job (25%), definitions (20%), context (10%), use (10%) and how readily a client connects (10%). A part that was not measured is left out, and a hidden instruction caps the score at 40. The state of vendors' MCP servers: method and numbers →

• generate_word_search

  Create a word-search puzzle (sopa de letras) from a list of words. Puzzles up to 10x10 with at most 10 words are free and unlimited; bigger ones use the free puzzles each client gets. Keeps native letters (Ñ, Ç, Ã, Ä, ẞ, È…) as one cell…

• fill_word_search

  Completes a word search: takes the grid from generate_word_search (empty cells are "-") and fills them with random letters in the chosen language, with accents on or off. Letters follow how common they are in that language. Pass the…

• stylize_text

  Turns text into Unicode styles for social media bios and posts: bold, italic, script, fraktur, monospace, circled, squared, fullwidth, small caps, strikethrough, underline and more (22 styles). Accents are kept: an accented letter becomes…

• list_styles

  The Unicode text styles stylize_text offers, with the id to pass, an English name and a category (bold-italic, sans, script, gothic, mono, enclosed, decoration, other).

• crossword

  Lays out a crossword from words with clues. Returns two matrices of the same size: puzzle (the game position: "-" is a blank cell, a word's number is on its first cell, "0" marks the other cells where a letter goes, and "a/d" such as…

• sudoku

  Creates a sudoku with exactly one solution. Returns puzzle (0 = empty cell) and solution. Sizes 4, 6, 9 (default), 12 and 16; difficulty 1 easy (most clues) to 4 expert. Free, no usage limit. The same seed gives the same sudoku.

• solve_sudoku

  Solves a sudoku grid (0 = empty cell; sizes 4, 6, 9, 12, 16) and says whether the solution is the only one. Free, no usage limit.

• list_languages

  Languages Lettras supports, with the native letters each one adds to its grid alphabet.