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

With no annotations provided, the description carries the burden of behavioral disclosure. It does this well by clearly flagging that carbon/balanced modes use a trailing historical production-mix profile, are experimental, and support no emissions-reduction claim. This prevents a likely misinterpretation of the carbon objective, adding meaningful transparency beyond the schema.

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?

Two sentences with no filler: the first front-loads the tool's purpose, and the second efficiently covers a critical caveat about the experimental modes. Every sentence 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?

The description covers purpose and an important behavioral caveat, but there is no output schema and the description does not explain what the returned ranked windows look like or when to choose this over sibling tools. Given the 7-parameter schema with nested objects, a bit more guidance on expected output or usage context would improve completeness.

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 57%, with descriptions for count, tariff, objective, and duration_minutes. The description adds value by clarifying the objective parameter's experimental nature and 'household cost' semantics for tariff, but it does not compensate for the undocumented to, from, and zone parameters.

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 states a specific action and resource: 'Rank Home+ action windows by household cost.' This clearly communicates the tool's core function and distinguishes it from sibling tools that fetch raw prices, forecasts, or carbon data, though it does not explicitly name a sibling for contrast.

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: when you need cheapest cost-ranked action windows rather than raw price/forecast data. However, it does not explicitly state when to prefer this tool over siblings like get_prices or get_forecast, nor does it mention any exclusions or prerequisites.

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