start_charging

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It discloses one important behavior: 'auto-wakes if asleep'. However, it omits other relevant details like prerequisites (e.g., plugged in), potential side effects, or failure modes, making it a partial disclosure.

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 sentence of only eight words, front-loaded with the action and including a parenthetical clarifier. Every word is useful, and there is no redundancy or 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?

The tool is relatively simple, with optional parameters and no output schema. The description covers the core action and the auto-wake behavior, but lacks deeper context about charging requirements or returned information. Given the lack of annotations, the description is adequate but not exhaustive.

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 schema provides descriptions for all three parameters (vin, max_attempts, wait_for_completion), achieving 100% coverage. The tool description adds no additional parameter context, so the schema already handles parameter semantics, meriting the baseline score of 3.

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 primary action ('Starts charging the vehicle') with a specific verb and resource, distinguishing it from related sibling tools like stop_charging or set_charge_limit. The additional note 'auto-wakes if asleep' further clarifies its behavior.

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 but does not explicitly state when to use this tool versus alternatives such as set_charge_limit or set_charging_amps. No exclusionary or alternative tool guidance is provided, so it relies on the user/agent to infer from the name and context.

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