gas_vs_electric_car_calculatorGas vs Electric Car Cost Calculator — Compare the yearly fuel cost of a gas car versus an electric car. Enter miles, MPG, and rates to see annual savings, break-even years, and 5-year totals.
| Name | Required | Description | Default |
|---|---|---|---|
| mpg | Yes | ||
| kWhPerMile | Yes | ||
| annualMiles | Yes | ||
| evPricePremium | No | ||
| gasPricePerGal | Yes | ||
| electricityRate | Yes |
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 states the comparison and outputs, but does not mention limitations (e.g., ignoring maintenance, insurance, or total cost of ownership) or the role of the optional evPricePremium parameter. This is adequate but not deeply transparent.
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 only two sentences and front-loaded with the tool's purpose. However, the first clause simply repeats the title, which is redundant and could have been omitted. It remains efficient overall.
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 description lists the key outputs (annual savings, break-even years, 5-year totals) and some inputs, but fails to mention the optional evPricePremium parameter or any assumptions of the calculation. Without an output schema, the description could do more to clarify result structure and edge cases, though it is serviceable for a straightforward calculator.
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 has 0% description coverage, so the description must compensate. It mentions 'miles, MPG, and rates' but does not explicitly map to all six parameters. Importantly, kWhPerMile (electric car efficiency) and evPricePremium are omitted, leaving the agent to infer their purpose from bare parameter names. The added value over the schema is minimal.
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 compares yearly fuel cost between gas and electric cars, with specific outputs like annual savings, break-even years, and 5-year totals. This distinctly differentiates it from sibling calculators such as ev_charging_cost_calculator or electricity_cost_calculator.
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 provides clear context for when to use the tool: when comparing gas vs electric car fuel costs. It implies the inputs needed (miles, MPG, rates) and outputs produced, but stops short of explicitly mentioning alternative tools or exclusions, so it doesn't fully meet the top bar.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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