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

With no annotations, the description carries the burden of behavioral disclosure. It explains what the tool returns and that it works globally, but it does not mention edge cases such as polar day/night, missing sunrise/sunset values, time format, or how the UTC offset affects returned times beyond the schema.

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 two short sentences and both of them directly serve the goal. It is front-loaded with the core output and avoids redundant phrasing.

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 no output schema, the description names the expected results but does not describe their format or how edge cases behave. Combined with the schema, the definition is sufficient for basic calls but lacks some context for unusual locations and ambiguous timezone semantics.

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%, so all parameters are already documented with type and format. The description adds no meaningful information, whereas 'coordinate' and 'date' are broad restatements of the schema fields.

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 title and description clearly identify the tool as returning sunrise, sunset, and solar noon for a given coordinate and date. The phrase 'Works worldwide' adds meaningful scope, and the resource is distinct from the weather-focused sibling tools.

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 intended use is reasonably implied—request sun-event times for a location and date—but no explicit guidance is given about when to choose this tool over alternatives. The sibling list makes the distinction obvious, so the lack of direct comparison is a moderate gap rather than a severe one.

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