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NextArena MCP server

Which MCP servers are NextArena's own, from the official registry and from asking its own domain, whether they answer, and what they offer. A program checked each of these, nobody copied them from a product page.

read 2026-10-29

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Whose server it is
  • Registry nameco.nextarena/tournament-toolsverified in the MCP registry

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

When we asked itchecked 2026-10-29
  • Stateanswerschecked 2026-10-29
  • Tools6
  • Server calls itselfnextarena
  • Server version0.1.2
  • Protocol version2025-06-18

On 2026-10-29 the server answered initialize and tools/list without a sign-in. First answer in 131 ms.

Should an agent connect itNot proven either way yet
  • Its tools do Build a round robin or bracket draw, but not Publish a public event page with online registration; Stream matches with a live score bar.
  • Checked on 6 of the 7 days it takes to judge reliability.

Once connected

  • For "Build a round robin or bracket draw", the likely first call is get_supported_tournament_options.
  • Parameters are untyped or undescribed in 5 of 6 tools: check arguments before calling.

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.

Measured dailydaily checks: 6, the first on 2026-10-29
  • INITE MCP scoreafter a weeka score needs 7 daily checks: 6 so far
  • What an agent can do with it1 of 3 use cases
  • Answeredmeasuring6 of the 7 daily checks it takes to print a share
  • Median first answer162 ms
  • Space in an agent's context≈ 4,548 tokensthe definitions of all its tools (6), which an agent carries on every turn
  • Tool definitionsB · 86 of 100
  • Typed results0 of 6 toolsdeclared outputSchema: results come typed, read once
  • Parameters without a description: in 5 of 6

What an agent can do with it

  • can do · Build a round robin or bracket draw
  • cannot · Publish a public event page with online registration
  • cannot · Stream matches with a live score bar

Each of the product's use cases, put to Jev against this server's tool list: can an agent do it with these tools?

Worth a look

None of the five warning signs in these definitions.

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 →

Tools it offers6 tools · read 2026-10-29
  • get_supported_tournament_options

    Use for a generic tournament request with no confirmed sport or format, or to discover NextArena's supported sports, formats, entrant types and limits. Does not generate a tournament or select defaults. With no sport, ask Pickleball or…

  • generate_round_robin

    MANDATORY BEFORE CALLING: the user must have chosen BOTH sport and format for THIS tournament. If either is missing, ask instead of generating, or call get_supported_tournament_options to discover choices. Never infer sport or format from…

  • generate_americano

    MANDATORY BEFORE CALLING: the user must have chosen BOTH sport and format for THIS tournament. If either is missing, ask instead of generating, or call get_supported_tournament_options to discover choices. Never infer sport or format from…

  • generate_bracket

    MANDATORY BEFORE CALLING: the user must have chosen BOTH sport and format for THIS tournament. If either is missing, ask instead of generating, or call get_supported_tournament_options to discover choices. Never infer sport or format from…

  • generate_mexicano_round

    MANDATORY BEFORE CALLING: the user must have chosen BOTH sport and format for THIS tournament. If either is missing, ask instead of generating, or call get_supported_tournament_options to discover choices. Never infer sport or format from…

  • calculate_mexicano_standings

    MANDATORY BEFORE CALLING: the user must have chosen BOTH sport and format for THIS tournament. If either is missing, ask instead of generating, or call get_supported_tournament_options to discover choices. Never infer sport or format from…

How to connect

Add the server to your MCP client config. Claude Desktop, Cursor and most other clients read this shape:

{
  "mcpServers": {
    "tournament-tools": {
      "type": "http",
      "url": "https://www.nextarena.co/api/mcp"
    }
  }
}

Add it

Claude Code, in a terminal

claude mcp add --transport http nextarena https://www.nextarena.co/api/mcp

Add to CursorAdd to VS Code

claude.ai, ChatGPT and other clients: add https://www.nextarena.co/api/mcp as a custom connector in the settings.

Each line is something a program found when it went looking: the registry entry, the server's own answer, a spec that parses. A missing line means we did not find it, not that it does not exist.