NREL PVWatts Solar PV Production Estimate

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

Annotations already provide readOnlyHint, destructiveHint, idempotentHint, and openWorldHint. The description adds behavioral context (uses NSRDB data, returns specific fields) that complements annotations without contradiction. It does not discuss limitations or edge cases, but the annotations cover safety.

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 three sentences: purpose, data source, return fields + uniqueness. Each sentence adds necessary information without redundancy or fluff. It is efficient and front-loaded.

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?

With an output schema present, the description does not need to detail return values. It covers purpose, data source, uniqueness, and key return fields. It could mention required parameters or examples, but the schema covers those. Overall, it is complete for a tool with rich annotations and schema.

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 input schema has 100% description coverage for all 8 parameters. The tool description does not add any additional parameter-level information beyond what the schema already provides. It mentions 'global location,' which is consistent with latitude/longitude, but this is already clear from the schema descriptions. Therefore, the description adds minimal value for parameter semantics.

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 action ('Calculate'), the specific metric ('monthly and annual AC energy production in kWh'), and the domain ('residential or commercial solar PV system at any global location'). It also mentions the data source and return fields. The distinctiveness from siblings is asserted with a uniqueness claim.

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 explicitly states 'Unique — no other tool in this catalog estimates solar PV output,' which provides clear guidance on when to use this tool versus alternatives. It also gives context about using NSRDB data.

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