get_cost_savings

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

The description explains the calculation and the tariff input options, but with no annotations it carries the full burden. It does not disclose what happens if neither tariffKwh nor the env var is provided, nor does it mention output format or that it is a read-only calculation. The formula and input dependency are clear, but behavior under missing input is left undetermined.

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?

One concise sentence front-loaded with the tool's purpose and the input requirement. No wasted words or redundant content.

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 tool with one optional parameter, the description covers purpose, calculation, and input mechanism. It lacks a note on fallback behavior when no tariff is provided, but overall it is sufficiently complete given the tool's simplicity and the rich sibling tool context.

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 already fully describes tariffKwh (coverage 100%), so baseline is 3. The description adds value by introducing the FELICITY_TARIFF_KWH environment variable as an alternative source and by clarifying the parameter's role in the savings formula, which goes beyond the schema's basic unit description.

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 purpose: 'Estimated monetary savings from discharged energy × electricity tariff.' It specifies the exact formula and the resource (cost savings), distinguishing it from sibling tools about health, autonomy, and energy history.

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?

Provides clear usage context: 'Pass tariffKwh or set FELICITY_TARIFF_KWH env var.' This explains how to invoke the tool with the necessary input. However, it does not explicitly discuss when to prefer this over alternatives, though none of the sibling tools overlap with cost savings.

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