start_defrost

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

With no annotations, the description carries the burden, and it does disclose one behavioral trait: auto-wakes if asleep. However, it omits other relevant behaviors such as side effects on climate settings, whether the command is asynchronous (though wait_for_completion hints at it), or error/return behavior.

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 a single, concise sentence with no fluff. The key action is front-loaded, and the auto-wake note is a useful addition that earns its place.

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 simple command, the description covers the core purpose and one behavior, but lacks detail on return values or completion semantics, especially given there is no output schema and no annotations. The sibling context suggests this is a straightforward control command, so minimalism is somewhat acceptable, but a bit more context would help.

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 100%, so the schema already documents all three parameters. The description adds no extra parameter semantics beyond what is in the schema, so the baseline of 3 applies.

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 ('Starts') and resource ('max defrost mode'), clearly distinguishing it from siblings like start_climate and stop_defrost. It is immediately obvious what the tool does.

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 (defrosting) but provides no explicit guidance on when to choose this over alternatives like start_climate, nor any exclusions. The 'auto-wakes if asleep' note implies you may not need to call wake_vehicle first, but this is not framed as usage guidance.

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