start_zone

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

With no annotations, the description must carry the behavioral burden. It mentions max 180 minutes, but doesn't disclose side effects (e.g., does it stop other zones? does it require a device? what happens on errors? whether it reports success?). The description is minimal and doesn't cover expected behavior beyond the basic action.

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 concise sentence with no fluff. It states the action and a constraint (max 180 minutes). It is appropriately brief, though it could be more structured with parameter details. But as far as length goes, it's 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?

With no annotations, no output schema, and only 2 required parameters, the description omits critical context: return values, side effects, prerequisites, what happens if another zone is running, and how the 'device' parameter is used. The description is far from complete for an agent to invoke it safely.

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 coverage is 0% and the description doesn't explain any parameters. It mentions 'zone' and 'minutes' but doesn't add semantics like valid values, meaning of device, or how zone is identified. With 0% coverage, the description must provide this, and it doesn't.

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 clear verb ('Run') and resource ('a single zone') with a duration constraint (max 180 minutes). It differentiates from sibling 'start_zones' (plural) by specifying 'single zone'. However, it doesn't explicitly contrast with alternatives like 'run_schedule' or 'stop_watering', so it's not fully distinctive but clear enough.

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?

No guidance on when to use this tool vs alternatives like start_zones, stop_watering, or run_schedule. It doesn't mention exclusions or prerequisites. The only usage hint is that it runs a single zone, which implicitly contrasts with start_zones, but no explicit decision guidance is given.

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