PureScript MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes several important behaviors: the automatic stopping of existing servers, the single-instance constraint, the random port selection with return value, and the absolute path requirement. It doesn't mention error handling, timeouts, or resource consumption, but covers the most critical operational aspects.

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 efficiently structured with five concise sentences, each delivering essential information. It's front-loaded with the primary purpose, followed by operational constraints, prerequisites, port behavior, and path requirements. There's no redundant or unnecessary content - every sentence earns its place.

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?

For a server initialization tool with no annotations and no output schema, the description provides strong coverage of the critical behaviors and constraints. It explains the prerequisite relationship with other tools, the singleton nature of the server, the automatic conflict resolution, and the port selection behavior. The main gap is the lack of information about what the response contains beyond the port number.

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?

With only 25% schema description coverage (only 'project_path' has a description), the description compensates by emphasizing the absolute path requirement for the critical 'project_path' parameter. While it doesn't detail the other three parameters, it establishes the core constraint that applies to the most important required parameter, adding meaningful context beyond the sparse schema documentation.

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 clearly states the specific action ('Start the PureScript IDE server') and its primary functions ('type checking, auto-completion, and error detection'). It distinguishes this tool from its sibling 'stop_purs_ide_server' by being the complementary start operation, and from other pursIde* tools by being the prerequisite server initialization.

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?

The description provides explicit guidance on when to use this tool: 'Required for all pursIde* tools to work' establishes it as a prerequisite. It also specifies when-not scenarios: 'Only run one at a time' and 'Automatically stops any existing server to prevent conflicts' tells the agent to avoid redundant invocations. The context of sibling tools reinforces this positioning.

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