serial_status

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, covering the safety profile. The description adds useful context about the exact fields shown and the optional port filtering behavior. It does not contradict the annotations and goes beyond them by clarifying the output content, which is valuable for an agent deciding whether to invoke it.

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 two sentences with zero fluff. The primary purpose is front-loaded, and the parameter usage note is concise and actionable. Every word contributes to understanding the tool's function and invocation, making it a model of efficiency.

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 optional parameter, no output schema, and annotations covering safety), the description is fully sufficient. It states what the tool does, the exact data returned, and how to filter. No critical information is missing for an agent to call it correctly, especially since the output format is implicitly described by listing the fields.

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 input schema fully describes the 'port' parameter with an example. The description adds semantics by explaining that omitting the parameter lists all sessions, which is not explicitly stated in the schema. Since schema coverage is 100%, the baseline is 3, but the description enhances understanding of the parameter's optionality and behavior, earning a 4.

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 tool's action ('Show every capture session') and specifies the data returned (state, uptime, counters, unread lines, log file path). It also implies the ability to filter by port, distinguishing it from sibling tools like serial_get_log or serial_get_recent that target specific aspects. The verb and resource are precise, making the purpose 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 gives a usage hint ('Omit ‘port’ to list all sessions') but does not explicitly explain when to use this tool over its siblings. With many serial-related tools available, it would benefit from stating that it provides a summary of all capture sessions, whereas other tools like serial_get_log retrieve specific logs or serial_get_recent fetch recent data. The omission of alternatives leaves the decision partly to inference.

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