Stop a running preview server by port number to free resources or end the preview session.
Stop a preview server started by this MCP process.
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "stop_preview_server"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| port | No |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It states the core action and the scope ('started by this MCP process'), which is useful, but it does not mention side effects (e.g., terminating a process), error behavior if the port is not running, or whether the operation is idempotent. Basic but adequate for a simple stop operation.
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, front-loaded sentence with zero filler words. It states subject, verb, and object efficiently, and every word earns its place. There is no redundancy or unnecessary detail.
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 simple tool with one optional parameter and no output schema, the description covers the core purpose and scope. It does not explain that the port is optional or that its default is 8000, but the schema provides that information. The missing elements (e.g., parameter usage) are minor for this tool's simplicity.
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?
Schema description coverage is 0%, and the description does not mention the 'port' parameter at all. The schema provides type, default, and range constraints, but the description adds no semantic meaning about which port to stop or how to determine it. The agent must infer the parameter's role from its name alone.
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 uses a specific verb ('Stop') and a clearly scoped resource ('preview server started by this MCP process'). This immediately distinguishes it from the sibling tool start_preview_server and any other server-related tools, making the tool's function unambiguous.
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 implies when to use this tool (to stop a preview server that was started by this process) but does not explicitly state the context, prerequisites, or alternatives. It names a scoping constraint ('started by this MCP process') but does not compare it to any sibling tools or say when not to use it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.