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RoxyAPI Astrology MCP server

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Arabic lots calculator - seven Hermetic parts including Part of Fortune and Spirit

post_astrology_arabic_lots
Read-only

Calculate the seven Hermetic lots (Arabic parts) for any birth moment, with day/night formulas from chart sect. Returns each lot's sign, degree, longitude, arc, and interpretation.

Instructions

Calculate the seven Hermetic lots (Arabic parts) for any birth moment. The lots are the Part of Fortune, Part of Spirit, Eros, Necessity, Courage, Victory, and Nemesis. Each lot is a sensitive point projected by arc from the Ascendant, with the day or night formula applied automatically from the chart sect. Returns the zodiac sign, degree, exact longitude, the arc used, and a plain language interpretation per lot, for Hellenistic and traditional astrology apps. Built on accurate tropical chart positions, no astronomy expertise needed.

Input Schema

NameRequiredDescriptionDefault
dateYesBirth date in YYYY-MM-DD format. Determines planetary positions for the specific calendar day.
langNoResponse language (BCP 47). Supported: en, tr, de, es, hi, pt, fr, ru, zh-Hans, zh-Hant. Defaults to en. Coverage varies by domain, and a field with no translation in the requested language returns English.en
timeYesBirth time in 24-hour HH:MM:SS format. Determines the Ascendant (rising sign) and house cusps. Use 12:00:00 if unknown.
compactNoSet true for the same data in a compact shape: arrays of same-shaped objects arrive columnar as {"__cols":[names],"__rows":[[values]]}. Lossless, typically 40 to 52 percent fewer tokens.
latitudeYesBirth location latitude in decimal degrees (-90 to 90). Positive = North, negative = South.
nodeTypeNoLunar node convention. "mean" is the smoothed average node, which always moves retrograde; "true" is the osculating node, which tracks the real perturbed node, oscillates up to about 1.5 degrees either side of the mean on a 173-day cycle, and can briefly turn direct. Neither is more correct and they almost always fall in the same sign. Applies to the North and South Node. True is the osculating node and the default, because it is what most Western chart software reports; mean is the smoothed node preferred by several evolutionary schools, so pass "mean" to match one. Nothing else in the chart changes, and the two agree on the sign except when the node sits within about 1.8 degrees of a cusp. Defaults to "true".true
timezoneYesTimezone: an IANA name (e.g. "America/New_York", "Europe/London", or `cities[0].timezone` from /location/search) or decimal hours from UTC (e.g. -5 for EST, 5.5 for IST). An IANA name is resolved to the offset in force at the given date and time.
longitudeYesBirth location longitude in decimal degrees (-180 to 180). Positive = East, negative = West.
houseSystemNoHouse system used to place the Sun, which determines the chart sect (day when the Sun is above the horizon, night when below) and therefore which lot formula applies. Placidus (default), Whole Sign, Equal, or Koch.placidus

Output Schema

NameRequiredDescriptionDefault
lotsYes
sectYes
summaryYes
birthDetailsYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed2 schema fields changedv1.1.2
    • changedInput schema / examples
      Previous value: -[
      -  {
      -    "date": "1990-07-15",
      -    "latitude": 40.7128,
      -    "longitude": -74.006,
      -    "time": "14:30:00",
      -    "timezone": -5
      -  }
      -]New value: +[
      +  {
      +    "date": "1990-07-15",
      +    "latitude": 40.7128,
      +    "longitude": -74.006,
      +    "time": "14:30:00",
      +    "timezone": "America/New_York"
      +  }
      +]
    • changedInput schema / properties / timezone / example
      Previous value: --5New value: +"America/New_York"
  2. First observedv0.1.0

TDQS

A3.9/5.0
Behavior4/5

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds real behavioral context: the lots are arc-projected from the Ascendant, and the day/night formula is selected automatically from chart sect. It also discloses the return contents per lot, though nothing about auth or limits.

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

Conciseness4/5

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

Front-loads the core action and the lot list, then the mechanism and returns. The closing 'Built on accurate tropical chart positions, no astronomy expertise needed' is mildly promotional, but the rest is dense and waste-free.

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

Completeness4/5

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

An output schema exists, so return values need not be detailed, yet the description still summarizes them. Annotations cover safety and all params are schema-documented, leaving only the sibling-routing gap. Adequate for a read-only calculator.

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 schema already documents all nine parameters thoroughly. The description adds only an indirect note tying chart sect to the applied formula, without clarifying individual parameters beyond the schema baseline.

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?

States a specific verb ('Calculate') and resource ('the seven Hermetic lots (Arabic parts)'), then enumerates all seven lots by name. It is immediately distinguishable from siblings like post_astrology_natal_chart or post_astrology_houses.

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

Usage Guidelines3/5

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

The description gives audience context ('for Hellenistic and traditional astrology apps') and scope ('for any birth moment'), which implies when it applies. However, it never names an alternative or states when NOT to use it versus the broader natal chart tool that likely also surfaces lots.

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