Carbon intensity

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds meaningful behavior beyond annotations: 5-minute resolution, optional forecast, and the specific return values (latest reading, range over the window, greenest upcoming period). No contradiction with annotations.

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?

Three sentences with no redundancy: definition, use case, and return values are front-loaded and each earns its place. There is no filler or repeated schema information.

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 read-only look-up tool with no output schema, the description adequately covers what the tool does, when to use it, and what it returns. It could be more complete by explicitly contrasting with sibling tools, but that gap is minor given the strong schema and annotations.

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 coverage is 100%, so the schema documents all parameters well. The description adds value by linking the forecast flag to the 'greenest upcoming period' return and the start/end window to the returned range, which enriches the schema's bare parameter descriptions.

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 the resource (CO2 per kWh on the Danish grid), resolution (5-minute), and optional forecast, and clearly distinguishes it from siblings like get_electricity_prices and get_power_system_now by its focus on carbon intensity. The use-case phrasing 'Use it to answer when to run something power-hungry' makes the tool's purpose actionable.

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?

It explicitly says when to use the tool ('when to run something power-hungry'), giving clear context. It doesn't explicitly name sibling alternatives or exclusion conditions, but the unique carbon-intensity resource makes the intended use evident against the sibling list.

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