Serial Close Session

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

Annotations already mark the tool as destructive and idempotent. The description adds useful side-effect information by noting that the port lock is released, which goes beyond the schema. It does not describe failure behavior, but the annotations and simple scope make this acceptable.

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 one compact sentence with no filler, front-loading the action and object. Every word contributes to meaning.

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 one-parameter, straightforward closure tool, the essential purpose and side effect are covered. It could explicitly state that a session must be open first or point to how to find sessionId, but the sibling tools and idempotentHint provide enough lifecycle context.

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%, so the description must compensate by explaining the sessionId parameter. It only reuses the word 'session' without clarifying where the ID comes from, its format, or how it relates to sibling session tools. The parameter name is somewhat self-explanatory, but the description adds minimal value.

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 verb ('Close') and a specific resource ('a serial session'), with an immediate consequence ('release its port lock'). It clearly distinguishes the tool from siblings like serial_open_session and 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 implies usage at the end of a serial session, but it does not explicitly say when to use it versus alternatives or mention that the session must already be open. The agent must infer the appropriate context from the sibling tool names.

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