set_lines

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

With no annotations provided, the description carries the full behavioral burden and does so well: it discloses that the lines are held, that None leaves a line unchanged, that True/False drive the output, and that the tool is refused in read-only mode. This goes beyond the bare schema and gives the agent accurate state-change expectations.

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 main action is front-loaded in a single sentence, followed by compact use cases and caveats. Every sentence adds information; there is no filler or repetition of schema fields.

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 three-optional-parameter tool with an output schema, the description is nearly complete: intent, dtr/rts semantics, safety guidance, and read-only behavior are all covered. The only notable gap is the connection parameter, which is left to be inferred rather than explained.

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 compensates for zero schema-description coverage by explaining dtr and rts semantics ('set it True to transmit, False to stop', 'DTR False' for reset, None to keep unchanged). However, the connection parameter is never explained, so a third of the parameters still lack semantic guidance.

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 and resource: 'Set the DTR and/or RTS output lines and hold them.' It also distinguishes itself from pulse_line by noting that pulse_line is safer for keying a transmitter, so the agent can tell it apart from a sibling without opening schemas.

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?

It gives concrete when-to-use scenarios: keying a PTT wired to RTS/DTR, holding an Arduino in reset, and signaling a modem. It also gives an exclusion by recommending pulse_line as safer for PTT use, and explicitly warns 'Refused in read-only mode.'

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