Charging time and energy estimate

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

Annotations only say read-only and open-world, so the description adds meaningful behavior: it explains the estimation inputs (energyAvailable, configured amp limit, and the car's own time-to-full) and conditional logic ('when available', 'when charging'). This does not contradict the readOnlyHint.

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 dense sentence with the core purpose front-loaded and supporting estimation logic packed efficiently afterward. It is compact but slightly dense; the parenthetical field reference could be trimmed without losing much value.

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 an output schema present and fully documented optional parameters, the description covers the key inputs and calculation sources an agent needs. It falls short only in not orienting the agent toward sibling alternatives or clarifying where the target charge level originates.

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% for both parameters, so the description need not re-document vin/phases. It adds algorithmic context about amp limit and energy sources, but no additional parameter syntax or constraints beyond the schema.

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 opens with a specific verb and resource: it estimates energy and time needed to reach a target charge level from current SoC. This distinguishes it from siblings like get_target_soc and get_battery without needing to name them.

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 is given on when to use this tool versus alternatives such as plan_cheapest_charge or get_charge_now; it also states no prerequisites or exclusions. The context is inferable but not explicit.

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