serial_close

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

The description explains that the connection ID becomes invalid after closing, which is beyond the annotations. Annotations indicate idempotentHint=true and destructiveHint=false, which align with the description (closing an already closed connection likely returns an error, not destruction). No contradictions found.

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 concise (a few sentences), well-structured with sections for description, parameters, and returns. It front-loads the core purpose. Minor redundancy in the first line repeating the title, but overall efficient.

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?

Given the tool's simplicity (one parameter, output schema provided, idempotent annotation), the description is complete. It covers input, output examples, and side effects (invalidated ID). No gaps identified.

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 description explicitly documents the single parameter 'connection_id' with its purpose and origin ('Connection ID returned by serial_open'), adding value beyond the input schema which only provides a brief description. Schema description coverage is 0%, so the description carries the full burden, and it does so well.

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 'Close a serial port connection' and explains that it closes the specified port and releases resources. It clearly identifies the action (close) and the resource (serial port connection), distinguishing it from sibling tools like serial_open or serial_read.

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 mentions that the connection ID becomes invalid after closing, implying it should be used after a successful serial_open. However, it does not explicitly state when to use this tool vs alternatives (e.g., if a connection is already closed, no action needed) or provide explicit when-not-to-use guidance.

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