Professor Otter MCP server

• Registry namecom.professorotter/activitiesverified in the MCP registry

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

• Stateanswerschecked 2026-10-25
• Tools6
• Server calls itselfprofessor-otter
• Server version1.0.0
• Protocol version2025-06-18

On 2026-10-25 the server answered initialize and tools/list without a sign-in. First answer in 140 ms.

• Its tools do print word searches for car trips, but not solve sudoku and logic puzzles at the kitchen table.
• Checked on 2 of the 7 days it takes to judge reliability.

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 scoreafter a weeka score needs 7 daily checks: 2 so far
• What an agent can do with it1 of 2 use cases
• Answeredmeasuring2 of the 7 daily checks it takes to print a share
• Median first answer225 ms
• Space in an agent's context≈ 1,233 tokensthe definitions of all its tools (6), which an agent carries on every turn
• Tool definitionsA · 97 of 100
• Typed results6 of 6 toolsdeclared outputSchema: results come typed, read once

• Parameters without a description: in 1 of 6

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 (30%), doing the product's job (25%), definitions (20%), context (10%) and use (15%). 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 →

• list_activities

  List the Professor Otter printable activities (word searches, color by number, coloring pages, mazes, dot-to-dot, drawing practice, criss-cross, word scrambles, spot the difference, sudoku, games, secret codes, bingo, nonograms) with how…

• search_activities

  Search every printable activity by title, topic or a word in the puzzle, like the site's search box. Each query word must start a word in the puzzle ("ant" finds Ants, not Elephant). Narrow by activity or level if you like. Each hit…

• get_activity

  Get one printable puzzle as Markdown (description, level, word list or color key) with its play URL and its PDF URL. A puzzle PDF has an answer key. A game or drawing practice PDF does not. Use an activity and slug from search_activities.

• show_word_search

  Show a word search a child can play in the chat: drag across the letters to find each word, and found words cross off the list. Also returns the grid as text and a link to print the PDF. Pass a seed for a new grid; a slug and seed always…

• make_word_search

  Turn a list of 4 to 20 words, like a child's spelling list, into a word search they can play in the chat, with a link to print it as a PDF with an answer key. Paste the list as one string or pass the words as an array. A word longer than…

• list_products

  List the Professor Otter shop: printable PDF books, topic packs and the Everything Bundle, with prices and availability. Checkout is a browser page on the shop. Send the person there; never collect payment details or try to buy for them.