Close an open serial port connection to release it for other programs. Optionally close all connections at once.
Close a serial port and free it for other programs.
Args: connection: Which connection to close (name from connect). Default: the current one. all_connections: Close every open port.
| Name | Required | Description | Default |
|---|---|---|---|
| connection | No | ||
| all_connections | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.3.2Input schema / properties / all_connectionsAdded value: +{
+ "default": false,
+ "title": "All Connections",
+ "type": "boolean"
+}Input schema / properties / connectionAdded value: +{
+ "default": "",
+ "title": "Connection",
+ "type": "string"
+}v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden for behavioral disclosure. It mentions that closing frees the port for other programs, but it does not disclose side effects such as terminating ongoing communication, whether the action is reversible, or what happens if no connection exists. This is minimal for a mutation-like 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 succinct and well-structured. The main purpose is stated upfront, and the argument explanations are concise with no filler or redundant content.
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 description covers the parameters and the primary effect, but it lacks usage guidance and behavioral nuance. It doesn't mention error conditions or how to recover, though the output schema exists so return values aren't needed. For a simple disconnect operation, it is adequate but not comprehensive given the absence of annotations.
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 zero per-parameter descriptions, so the tool description must compensate. It clearly explains both parameters: 'connection' identifies the specific connection and defaults to the current one, and 'all_connections' closes every open port. This adds meaningful semantics beyond the schema's bare properties.
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 action and resource: 'Close a serial port and free it for other programs.' This is specific and distinguishes the tool from siblings like 'clear_buffer' (which clears data) and 'connect' (which opens a port).
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 does not explicitly state when to use this tool versus alternatives. It only implies usage when you want to close a port, but it lacks conditions, prerequisites, or guidance on when not to use it. No alternative tools are mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.