Get sunrise, sunset, and twilight times for any location using US Naval Observatory data. Also returns moonrise and moonset.
| Name | Required | Description | Default |
|---|---|---|---|
| tz | No | UTC offset in hours (e.g. -5 for EST, 1 for CET). Default: 0 (UTC) | |
| lat | No | Latitude (default: 40.7128 — New York City) | |
| lon | No | Longitude (default: -74.0060 — New York City) | |
| date | No | Date in YYYY-MM-DD format (default: today) |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden. It mentions the data source (US Naval Observatory) but does not disclose rate limits, accuracy, or how time zone handling affects results. Adequate but not comprehensive.
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 clear sentences with no wasted words. Could be slightly more structured with a note on return format, but efficient.
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?
No output schema exists, but the description does not explain the return format or possible errors. For a tool with 4 parameters and no annotations, this is incomplete.
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 coverage is 100% with all parameters described. The description adds no additional meaning beyond the schema, so baseline of 3 is appropriate.
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 verb 'Get' and the resource 'sunrise, sunset, and twilight times' and also mentions moonrise/moonset. It distinguishes from sibling tools like 'get_current_time' (just time) and 'get_moon_phases' (phases only).
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?
No guidance is provided on when to use this tool versus alternatives. It does not mention context or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.