Generate UML sequence diagrams with lifelines, sync/async call arrows, and return messages. Provide an output path and spec to produce a Draw.io diagram.
Generate a UML sequence diagram with lifelines, sync/async call arrows, and return messages.
| Name | Required | Description | Default |
|---|---|---|---|
| spec | Yes | ||
| output_path | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v2.0.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full burden of behavioral disclosure. It only states the generation action without describing side effects like file creation, overwriting behavior, error handling, or the structure of the return value. The agent cannot anticipate what happens when the tool runs.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single concise sentence with no redundancy. It is front-loaded with the primary action, but the brevity sacrifices necessary detail, making it more under-specified than effectively concise.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool has a complex spec object with no schema definition and an output schema that is not described. The description fails to mention the spec format, required parameters, output behavior, or any dependencies. It is entirely inadequate for a tool with this complexity, even with the presence of an output schema.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema has 0% description coverage and the description does not explain the 'spec' object or the 'output_path' string. With no parameter details in either the schema or the description, the agent has no idea what the spec should contain or how to construct it, making correct invocation impossible.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description states a specific action ('Generate a UML sequence diagram') with concrete elements (lifelines, sync/async call arrows, return messages), which distinguishes it from sibling tools like generate_er_diagram or generate_c4_diagram. It clearly identifies the resource type and the key features, though it omits the output_path and spec parameters from the sentence.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives such as generate_c4_diagram or generate_smart_diagram. There is no mention of scenarios, prerequisites, or exclusions, leaving the agent to infer the appropriate context from the name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.