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CycleCalcs Astronomy

by com.cyclecalcs

Sunrise, sunset and twilight

astro_sun
Read-only

The complete solar day for one location: sunrise, sunset, solar noon, day length, civil, nautical and astronomical twilight boundaries, and explicit polar day/night status at high latitudes. Location required. For a series, send start and end (step is whole days, e.g. "1d" or "7d"). For "is it dark enough to observe" prefer astro_dark_window; for a broad snapshot prefer astro_sky_today.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
tzNoIANA timezone like "Europe/Lisbon" to render event times in local time. Optional; a resolved place supplies its own timezone.
endNoLast day of a range. ISO 8601 UTC date or datetime, e.g. "2026-08-06" or "2026-08-06T21:00:00Z". Omit for the current moment. Years 1700 to 2200 only; outside that range the API refuses with DATE_OUT_OF_RANGE because the ephemeris is not reliable there.
latNoLatitude in decimal degrees, north positive. Send lat and lon together.
lonNoLongitude in decimal degrees, east positive (Lisbon is about -9.14). Send lat and lon together.
dateNoSingle day to report, ISO 8601 UTC date or datetime, e.g. "2026-08-06" or "2026-08-06T21:00:00Z". Omit for the current moment. Years 1700 to 2200 only; outside that range the API refuses with DATE_OUT_OF_RANGE because the ephemeris is not reliable there.
stepNoRange stride in whole days, e.g. "1d", "7d", "30d". Default "1d".
placeNoPlace name instead of lat/lon, as "City" or "City,CC" with an ISO country code, e.g. "Lisbon,PT". Resolved server-side; the response then carries a required GeoNames CC BY 4.0 credit in its attribution field, which must be preserved when shown.
startNoFirst day of a range (use with end instead of date). ISO 8601 UTC date or datetime, e.g. "2026-08-06" or "2026-08-06T21:00:00Z". Omit for the current moment. Years 1700 to 2200 only; outside that range the API refuses with DATE_OUT_OF_RANGE because the ephemeris is not reliable there.
cursorNoOpaque pagination cursor from a previous result's next_cursor. Send it with the same start/end arguments as the first page.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
dataYesThe complete solar day for one location, or one row per day in range mode.
rightsNoEither unrestricted, or attribution_required when third-party place data was used. When attribution_required, the attribution line must be shown.
warningsNoMachine-readable notices about this answer. Present only when non-empty. Never changes whether the call succeeded.
attributionNoThe credit line to display verbatim when rights is attribution_required.
next_cursorNoPresent only when more rows exist. Send it back with the SAME start/end arguments as the first call to get the next page.
not_computedNoData this API deliberately does not serve, and why. Present only when the question touched such a field. An absence named here is information: treat it as "withheld", never as "none exists".

TDQS

A4.5/5.0
Behavior4/5

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

Annotations already mark the tool read-only and closed-world, so the bar for transparency is lower. The description adds meaningful behavior: it returns explicit polar day/night status, requires a location, and supports series over whole days. No contradictions with annotations, and it doesn't hide side effects or failure modes.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences: what it returns, how to request series, and when to prefer alternatives. Every sentence earns its place, front-loaded with the core purpose, and avoids repetition of schema details.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's moderate complexity (9 params, anyOf location requirement, output schema present), the description covers the full usage envelope: scope of results, how to specify a range, and which sibling tools to use for adjacent needs. The output schema handles return-value details, so nothing essential is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the parameter descriptions carry the full semantic load. The tool description adds little beyond noting that location is required and that step is in whole days, both of which are already clear from the schema. This matches the baseline of 3 for high schema coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a precise resource and scope: 'The complete solar day for one location' and enumerates specific outputs (sunrise, sunset, solar noon, day length, twilight boundaries, polar day/night). This distinguishes it from siblings like astro_dark_window and astro_sky_today, which are explicitly named as alternatives.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives direct usage context: location is required, series are created with start/end plus a whole-day step, and it explicitly says when NOT to use it ('For "is it dark enough to observe" prefer astro_dark_window; for a broad snapshot prefer astro_sky_today'). This fully satisfies the when-to-use vs alternatives criterion.

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

All CycleCalcs Astronomy toolsInspect
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TDQS

A4.4/5.0
Disambiguation5/5

Each tool targets a distinct observational need: dark windows, eclipses, geocoding, moon state, phase calendar, planet overview, planet events, precise positions, rise/set times, broad snapshot, and solar day. Cross-references among descriptions prevent ambiguity despite overlapping data like rise/set times appearing in several tools.

Naming Consistency4/5

All tools share the astro_ prefix and use snake_case, creating a predictable pattern. The naming is mostly noun-based (the object of interest), but astro_find_place and astro_rise_set break the pure-noun pattern, introducing a slight inconsistency.

Tool Count5/5

With 11 tools, the server covers the major areas of practical astronomy without redundancy. Each tool provides a distinct calculation or data set, and the count fits the expected scope for an astronomy API.

Completeness4/5

The tool set covers solar, lunar, planetary, eclipse, positional, and visibility needs comprehensively. However, there is no explicit tool for equinoxes and solstices, which would be a natural inclusion for a cycle-focused astronomy server, creating a minor gap.

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