plantuml-mcp

Decode PlantUML URL

decode_diagram_url

Recover PlantUML source code from a PlantUML server URL or encoded string to edit or inspect the original diagram syntax.

Instructions

Recovers the PlantUML source code from a PlantUML server URL or encoded string.

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": {
      "url": "<url>"
    },
    "name": "decode_diagram_url"
  }
}

Input Schema

Name	Required	Description	Default
`url`	Yes	PlantUML URL (e.g. https://www.plantuml.com/plantuml/png/...) or encoded string

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Oct 21, 2026

TDQS

B3.4/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full behavioral burden. It identifies the transformation but omits whether it fetches remote URLs, how errors are handled, whether it is idempotent, or if it has side effects. It adds little beyond the purpose statement.

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 sentence that front-loads the action and result with zero filler. It is appropriately sized for a simple decode tool.

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 decode tool with full parameter schema coverage and no output schema, the description covers what it returns ('PlantUML source code') and the input types. It is nearly complete, missing only peripheral behavioral details such as remote-fetch requirements.

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 100% and the single 'url' parameter is fully described. The description repeats the accepted input types ('PlantUML server URL or encoded string') without adding format details beyond the schema, so the baseline 3 is appropriate.

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?

States a specific verb ('Recovers') and resource ('PlantUML source code') with the input scope ('PlantUML server URL or encoded string'). This inherently distinguishes it from render_diagram and get_diagram_urls, which handle rendering and URL retrieval.

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?

No when-to-use guidance, prerequisites, or named alternative tool. An agent can infer usage from the purpose, but the description provides no routing information to distinguish this from render_diagram or get_diagram_urls.

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

Deploy Server