Minecraft Mods MCP

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use_instance

Select a CurseForge Minecraft instance by name or unique substring to set the active target for subsequent world, mod, and configuration operations.

Instructions

Select the current CurseForge instance for later world/mod/config tools.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "name": "<name>"
    },
    "name": "use_instance"
  }
}

Input Schema

Name	Required	Description	Default
`name`	Yes	Instance name or unique substring, e.g. ATM10

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Sep 8, 2026

TDQS

A4/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the behavioral burden. It discloses that an instance is selected and retained 'for later' tools, implying persistent state. However, it does not say whether the instance must already exist, whether a new selection replaces the previous one, or what happens on invalid names.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

A single, front-loaded sentence states the action and purpose with zero filler. Every word earns its place, making it highly scannable for an agent.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple one-parameter state-setting tool, the description is nearly complete: it explains what the tool does and why it is used. It omits details like return value and error behavior, but these are minor for this tool and no output schema exists to carry that burden.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema description fully covers the single 'name' parameter with an example ('ATM10'), so the schema already carries the semantic weight. The tool description adds no additional parameter detail, which is acceptable given the 100% schema coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Select') and a specific resource ('the current CurseForge instance'), and states its intended role ('for later world/mod/config tools'). This clearly distinguishes it from sibling tools like list_instances/get_instance, which retrieve or list rather than set a working context.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The phrase 'for later world/mod/config tools' explicitly conveys when this tool is appropriate: before using instance-scoped operations. It gives clear usage context, though it does not explicitly name alternatives or state when not to use it, which is a minor gap.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.