rhino_direct_irradiance

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so no contradiction; the description adds value by identifying the model family (Bird + Kasten-Young), defining turbidity scale (1 = very clear, 7 = industrial haze), and explicitly noting it is a pure calculation with no document edits. This goes beyond what the annotations provide.

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 compact, first sentence states the output and model, second defines key inputs, third disambiguates from document-editing tools. No filler, and the most decision-relevant information is 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?

An output schema exists, so return-value details are not the description's job. For a single-required-param calculation tool with read-only and idempotent annotations, the description is mostly complete, but it omits which params use defaults, that latitude/longitude/timezone defaults correspond to a specific location, and guidance about the clear-sky assumption limitations (e.g., no clouds).

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 0%, so the description must compensate, but it only mentions turbidity, altitude, and site inputs in broad terms. It does not explain latitude/longitude behavior, timezone_offset_h semantics, or the meaning of the single required datetime_iso beyond what the schema's example provides. The default geolocation (Seoul) is also left unexplained.

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 identifies a specific calculation (clear-sky DNI in W/m^2), names the exact models (Bird + Kasten-Young), lists inputs (turbidity, altitude), and explicitly declares 'Pure calculation — no doc edits', which sharply distinguishes it from Rhino geometry/document-editing siblings.

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 this is for clear-sky irradiance estimation when a pure calculation is needed, but it never names sibling alternatives like rhino_solar_exposure_estimate or rhino_sun_position, nor states when those would be preferable. The 'no doc edits' note hints at a read-only use case, but there is no explicit when/when-not routing.

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