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Create map

create_map

Creates a new RPG Maker MV map, registers it in MapInfos.json, and returns its map ID. Optionally fills layer 0 with a ground tile; use paint and event tools afterward.

Instructions

Create a new map: writes MapXXX.json and registers it in MapInfos.json. The map starts empty unless fill is given (a ground tile for layer 0); afterwards use paint_tiles to paint it, get_tileset_info to choose tiles and add events with the event tools. Returns the new map id.

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": "create_map"
  }
}

Input Schema

NameRequiredDescriptionDefault
fillNoOptional tile to fill layer 0 with, e.g. {sheet:'A2', kind:16} for grass
nameYes
widthNo
heightNo
parentIdNoParent map id in the editor tree (0 = top level)
tilesetIdNo

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changedv0.5.1
    • addedInput schema / properties / fill
      Added value: +{
      +  "anyOf": [
      +    {
      +      "maximum": 8191,
      +      "minimum": 0,
      +      "type": "integer"
      +    },
      +    {
      +      "additionalProperties": false,
      +      "properties": {
      +        "index": {
      +          "description": "Tile index, for sheets A5 (0-127) and B-E (0-255)",
      +          "type": "integer"
      +        },
      +        "kind": {
      +          "description": "Autotile kind, for sheets A1-A4 (A1 0-15, A2 16-47, A3 48-79, A4 80-127)",
      +          "type": "integer"
      +        },
      +        "sheet": {
      +          "enum": [
      +            "A1",
      +            "A2",
      +            "A3",
      +            "A4",
      +            "A5",
      +            "B",
      +            "C",
      +            "D",
      +            "E"
      +          ],
      +          "type": "string"
      +        }
      +      },
      +      "required": [
      +        "sheet"
      +      ],
      +      "type": "object"
      +    }
      +  ],
      +  "description": "Optional tile to fill layer 0 with, e.g. {sheet:'A2', kind:16} for grass"
      +}
  2. First observedv0.1.0

TDQS

A4/5.0
Behavior4/5

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

With no annotations, the description carries the burden and does well: it discloses that files are written, that MapInfos.json is mutated, that the map is empty by default unless fill is supplied, and that the new map id is returned. It does not mention validation behavior (duplicate names, bad tilesetId) or whether the change is undoable.

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?

Three tight sentences, front-loaded with the core action and effects, then the fill caveat, then the workflow and return value. No sentence is filler.

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?

No output schema exists, yet the description still states what is returned (the new map id), and it covers side effects and the empty-by-default behavior. The main remaining gap is the create_map vs generate_map distinction and any failure modes.

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?

Schema coverage is only 33%, so some compensation is needed; the description does explain `fill` semantics (a ground tile for layer 0) beyond the schema's own example. But width, height, tilesetId and parentId get no additional meaning from the description, leaving half the surface undocumented.

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

Purpose4/5

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

States a specific verb and resource ("Create a new map") and spells out the concrete effects: writing MapXXX.json and registering in MapInfos.json. It does not, however, distinguish itself from the sibling generate_map, which an agent could reasonably confuse with this tool.

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?

Gives an explicit follow-up workflow (paint_tiles to paint, get_tileset_info to choose tiles, event tools to add events), which is real routing guidance. It omits when to prefer create_map over generate_map or update_map, and any preconditions about the project state.

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