get_vitamin_d_window

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

With no annotations provided, the description takes on the full burden of behavioral disclosure. It discloses key behaviors: returns synthesisPossible=false when UV never reaches 3, adds minutesNeeded and UV at exact time with atTime, and notes that timezone is needed to avoid UTC defaults. It doesn't mention non-destructive nature, but that is implied by the read-only design. A clear, informative description.

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 a single paragraph but well-structured, front-loading the main outputs and usage boundaries. It is relatively concise given the complexity of the tool, but could be improved slightly with bullet points or clearer separation of concepts.

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?

Given the tool has 10 parameters, no output schema, and moderate complexity, the description provides solid context: main output fields, the condition for synthesisPossible, and the effect of atTime. It lacks a full list of return fields but covers enough for an agent to understand the tool's basic functionality.

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?

All 10 parameters have schema descriptions, but the tool description adds extra semantic meaning beyond those. It explains how atTime modifies the output, gives examples for exposedSkinFraction (e.g., 0.10 face+hands), and contextualizes age and skin type. This aids the agent in understanding parameter interactions.

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 tool's purpose: providing the solar vitamin D synthesis window for a single specific day at a location. It uses specific verbs like 'synthesis window' and 'returns', and explicitly distinguishes itself from the sibling tool get_vitamin_d_year for multi-day questions.

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 when to use this tool: 'Only for single-day questions', and provides a clear alternative: 'for months, seasons or when during the year, call get_vitamin_d_year instead'. This effectively differentiates from siblings and guides appropriate usage.

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