FigTreeKit-MCP

render_tree

Render Nexus files or Newick/Nexus tree content to PNG, PDF, SVG, or JPEG using FigTree, returning file paths and an optional base64 preview.

Instructions

Render a Nexus file (or tree content) to PNG/PDF/SVG/JPEG via the patched FigTree JAR; returns paths plus an optional base64 data URI preview. Applies background/foreground/label colour post-processing for raster formats.

Args: nexus_file: Path to a Nexus file (whitelisted; takes precedence). tree_content: Newick/Nexus content rendered through a base export. format: PNG|PDF|SVG|JPEG (default PNG). width: Image width in pixels. height: Image height in pixels. background_color: #RRGGBB background (raster post-process). foreground_color: #RRGGBB foreground (raster post-process). label_color: #RRGGBB protected label colour. jar_path: Explicit figtree_patched.jar path (default: app config / auto-detection). timeout: Max seconds for the JVM render call (default: app.render_timeout, normally 180). run_name: Optional artifact base name.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`width`	No
`format`	No
`height`	No
`timeout`	No
`jar_path`	No
`run_name`	No
`nexus_file`	No
`label_color`	No
`tree_content`	No
`background_color`	No
`foreground_color`	No

Output Schema

TableJSON Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 20, 2026

TDQS

B3.4/5.0

Behavior3/5

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

With no annotations, the description carries the full behavioral burden. It discloses useful traits (colour post-processing applies only to raster formats, default timeout ~180s, jar auto-detection/default config), but omits side effects such as where artifacts are written, whether rendering is expensive/blocking, or permission needs for whitelisted paths.

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

Conciseness4/5

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

Purpose is front-loaded in the first sentence, followed by a clean Args block; every line maps to a real parameter. Slightly terse for an 11-parameter tool but no wasted text.

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?

An output schema exists, so return values needn't be detailed, yet the description still notes paths plus optional base64 preview. Parameter and behavioral coverage are adequate for a moderate-complexity render tool, leaving only usage routing unaddressed.

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

Parameters4/5

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

Schema coverage is 0% (properties carry only titles/defaults), so the description must compensate, and it does: all 11 parameters are explained, including precedence rules, raster-only post-processing, defaults, and the resolution order for jar_path/timeout.

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 (render) and resource (Nexus file / tree content) plus outputs and the rendering engine, so the agent knows exactly what it produces. It does not, however, differentiate itself from siblings like style_tree or run_figtreekit_cli, which also touch tree rendering/output.

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

Usage Guidelines2/5

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

The only routing hint is that nexus_file 'takes precedence' over tree_content, which is an argument-precedence note rather than tool-selection guidance. There is no statement of when to choose this tool over style_tree, export_nexus, or run_figtreekit_cli.

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