Loading ToolBench
Renders PlantUML diagrams to SVG and PNG formats via the Model Context Protocol
Two well-named tools with clear, detailed descriptions that guide LLM selection. Input schemas are properly defined with required fields and additionalProperties=false. Descriptions (180+ chars each) explain WHAT the tool does, WHEN to use it, and renderer constraints. However, no output schema is documented, and error handling guidance is absent from the visible code. Tool names follow verb_noun pattern (render_*), and descriptions disambiguate between PNG (preferred for display) and SVG (explicit user request only). No parameter descriptions beyond the source field itself.
Render PlantUML source as a PNG image. Preferred tool for displaying diagrams: the resulting image is shown to the user automatically. Renderer: PlantUML 1.2026.6 (MIT build; ditaa and LaTeX math unavailable); write syntax compatible with this version.
Render PlantUML source as a downloadable SVG file (with an inline PNG preview). Use ONLY when the user explicitly asks for SVG format. To show a diagram to the user, use render_png instead. Renderer: PlantUML 1.2026.6 (MIT build; ditaa and LaTeX math unavailable); write syntax compatible with this version.
Output schema not documented. LLMs cannot infer what fields (base64, size, format, etc.) the response contains, forcing them to guess downstream processing.
No error handling guidance in tool descriptions. If PlantUML syntax is invalid or rendering fails, the description does not tell the LLM what to do next (retry, ask user, etc.).
Parameter 'source' lacks a description in the schema. While the field name is clear, a description explaining expected format (e.g., 'Valid PlantUML syntax for version 1.2026.6') would improve LLM accuracy.
No pagination or result limits documented. If rendering produces very large SVG/PNG outputs, no guidance on chunking or streaming is provided.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | D | 59 | 2026-07-28+ | v2 |