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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety bar is covered. The description usefully adds commercial behavior beyond that: free within the daily allowance, then $0.002 USDC per call via x402, which tells the agent about a metering/payment constraint not present in any structured field.

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 short sentences, the core purpose is front-loaded, and the secondary pricing note is properly subordinated. No filler or repetition.

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?

An output schema exists, so return shape need not be explained, and the tool has only two required date params. The description covers purpose and cost, but omits the lag/estimation caveat implied by 'actual or estimated' (e.g., data freshness or revision) that an agent might need.

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 'from' and 'to' are already fully documented as YYYY-MM-DD dates. The description's 'between two dates' adds no format, boundary, or range semantics beyond the schema, so the baseline 3 applies.

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?

States a specific verb+resource: wind (on/offshore) and solar generation with a date range, and the word 'Actual or estimated' implicitly separates it from the sibling forecast tools (wind-forecast, wind-forecast-peak). It stops short of naming any alternative, so it is clear but not fully self-differentiating.

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 gives no when-to-use guidance, no prerequisites, and no exclusions or alternatives, despite several overlapping siblings (wind-forecast, generation-history, generation-today). The only constraint conveyed is the two-date range, which is already implied by the parameters.

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