PPL Free Ground School MCP server

• Registry namecom.pplfree/ground-schoolverified in the MCP registry

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

• Stateanswerschecked 2026-10-21
• Tools5
• Server calls itselfcom.pplfree/ground-school
• Server version1.1.0
• Protocol version2025-06-18

On 2026-10-21 the server answered initialize and tools/list without a sign-in. First answer in 126 ms.

• Whether its tools do the product's job has not been judged yet.
• Checked on 1 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: 1 so far
• Answeredmeasuring1 of the 7 daily checks it takes to print a share
• Median first answer227 ms
• Space in an agent's context≈ 1,206 tokensthe definitions of all its tools (5), which an agent carries on every turn
• Tool definitionsA · 100 of 100
• Typed results0 of 5 toolsdeclared outputSchema: results come typed, read once

• Every tool passes all six checks.

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 →

• search_faa_knowledge

  Answer a US private-pilot (FAA) ground-school question from a source-cited curriculum. Use this whenever the user asks about FAA regulations, airspace, VFR weather minimums, weight and balance, aerodynamics, aircraft systems, navigation…

• get_practice_question

  Return private-pilot practice questions written for this course in the style of the FAA knowledge test (not actual FAA test questions), each with its answer choices, its topic, a question_id and a link to try it on pplfree.com. The…

• check_answer

  Grade the user's answer to a practice question from get_practice_question. Use this when the user replies with their choice (for example "B" or "I think it is C"): pass the question_id and their choice. Returns whether the answer is…

• get_lesson

  Fetch one full ground-school lesson: its summary, why it matters in flight, the learning objectives it covers, and a link to read it. Use this after search_faa_knowledge when the user wants the whole topic rather than a single answer, or…

• list_curriculum

  List the ground-school curriculum: modules and the published lessons in each, with their keys. Use this to orient yourself before get_lesson, to answer "what does the course cover", or to help a user plan what to study next.