unit_stop_tool

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

With no annotations, the description carries the full burden of behavioral disclosure. It does add a meaningful behavioral detail by stating 'Refused for units on the protected list,' but it does not mention failure modes, permission requirements, or side effects beyond the obvious 'stop' action. This is helpful but not comprehensive.

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 short sentences with no redundant phrasing. The core action is front-loaded, and the protected-list guardrail is a necessary caveat rather than filler.

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 lifecycle tool with an output schema, the description is mostly complete: it states what the tool does and flags an important constraint. The only notable gap is the lack of explicit guidance about when to prefer sibling tools, which is a minor omission for such a straightforward operation.

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 covers 100% of the parameters, and the unit_name field is already described as 'Systemd unit name.' The description does not need to add parameter details; it neither contradicts nor enriches the schema, so the baseline of 3 is appropriate.

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 ('Stop') and resource ('a unit'), which clearly distinguishes it from sibling tools like unit_start_tool, unit_restart_tool, and unit_reload_tool. Even without mentioning 'systemd' explicitly, the schema's 'unit_name' makes the target 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 main purpose is self-evident for a stop operation, and the note about protected units implies a restriction. However, it does not explicitly clarify when to use this tool instead of related lifecycle tools (e.g., unit_disable_tool for preventing startup at boot, or unit_mask_tool for stronger disabling).

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