opentoonz-mcp

Overview Schema Source Related Servers Discussions Admin

Opentoonz Draw Frame

opentoonz_draw_frame

Draw an RGBA frame using shapes, lines, text, or a composite PNG, then save it as an OpenToonz level drawing ready to import into a scene.

Instructions

Draw one RGBA frame with PIL primitives and save it as a level drawing.

ops: list of {"op": "rect|ellipse|line|polygon|polyline|text|image", ...} — see docs/tools.md. The "image" op composites an existing PNG, so art made elsewhere can join a drawn frame. Saved to /drawings/<level_name>..png, ready for opentoonz_import_images_as_level.

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": {
      "workspace": "<workspace>",
      "level_name": "<level_name>",
      "ops": "<ops>"
    },
    "name": "opentoonz_draw_frame"
  }
}

Input Schema

Name	Required	Default
`ops`	Yes
`frame`	No
`width`	No
`height`	No
`workspace`	Yes
`background`	No	#181a2e
`level_name`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.8.0Oct 17, 2026

TDQS

A3.7/5.0

Behavior4/5

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

With no annotations, the description carries the full burden and does disclose real behavior: PIL-based drawing, the supported op vocabulary, that the 'image' op composites an existing PNG, and the exact output path/format (<workspace>/drawings/<level_name>.<frame>.png). It omits overwrite semantics for an existing drawing file and any failure behavior, which are the notable remaining gaps for a file-writing tool.

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?

Front-loaded with purpose in the first clause, then ops structure, then the output location and downstream consumer. No filler sentences; the 'see docs/tools.md' pointer replaces what would otherwise be a long op-schema dump.

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

Completeness3/5

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

An output schema exists, so return values need not be explained, and the description covers the ops contract and output artifact. However, with no annotations and 0% schema coverage, the silent width/height/background parameters and the missing overwrite behavior leave the definition short of complete for a 7-parameter file-producing tool.

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 description coverage is 0%, so the description must compensate, and it only partly does: ops is explained with its type vocabulary and structure, and frame/level_name/workspace are inferable from the documented output path. Width, height, and background get no mention anywhere, leaving three of seven parameters 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 ('Draw one RGBA frame'), names the concrete technique (PIL primitives) and the artifact produced (a level drawing saved to a path). The word 'one' implicitly distinguishes it from the plural sibling opentoonz_draw_frames, though it never names that sibling explicitly, so the differentiation is left to inference.

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

Usage Guidelines3/5

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

Usage is only implied through the output path being 'ready for opentoonz_import_images_as_level', which hints at a downstream workflow. It never says when to use this tool rather than opentoonz_draw_frames (plural), opentoonz_tween_frames, or opentoonz_render_frame, and gives no exclusions or prerequisites.

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