astroway-mcp

Official

by astroway

Overview Schema Source Related Servers Discussions Admin

TypeScript

Remote

Synastry Element Balance

astroway_relational_synastry_element_balance

Read-onlyIdempotent

Compare the elemental and modality balance of two natal charts, showing fire, earth, air and water tallies for each person and the pair, with dominant and missing elements.

Instructions

Element (fire/earth/air/water) and modality (cardinal/fixed/mutable) tallies for each chart and the combined pair, with dominant and missing elements.

[Group: Comparisons] [Endpoint: POST /v1/synastry/element-balance] [Required: chart1, chart2] [Cost: 50 credits (Tier 3)]

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "chart1": "<chart1>",
      "chart2": "<chart2>"
    },
    "name": "astroway_relational_synastry_element_balance"
  }
}

Input Schema

Name	Required	Description	Default
`chart1`	Yes	Birth data for a single natal chart. Required: date (YYYY-MM-DD), time (HH:mm:ss), latitude and longitude in decimal degrees. The short forms lat, lon, lng and tz are rejected with 400 INVALID_FIELD; pass the full names. timezoneOffset is hours from UTC and defaults to 0, meaning UTC; send timezone instead (an IANA name such as Europe/Kyiv, or auto) and the offset for that date is worked out, summer time included. city is a display label only: nothing here geocodes it, so it never stands in for coordinates. houseSystem is a single house-system letter, P by default; a name such as "Placidus" is refused, and the case matters because I and i are two different Sunshine systems.
`chart2`	Yes	Birth data for a single natal chart. Required: date (YYYY-MM-DD), time (HH:mm:ss), latitude and longitude in decimal degrees. The short forms lat, lon, lng and tz are rejected with 400 INVALID_FIELD; pass the full names. timezoneOffset is hours from UTC and defaults to 0, meaning UTC; send timezone instead (an IANA name such as Europe/Kyiv, or auto) and the offset for that date is worked out, summer time included. city is a display label only: nothing here geocodes it, so it never stands in for coordinates. houseSystem is a single house-system letter, P by default; a name such as "Placidus" is refused, and the case matters because I and i are two different Sunshine systems.

Output Schema

Name	Required	Description	Default
`chart1`	No
`chart2`	No
`balance`	No
`combined`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.6.1Nov 9, 2026

changedInput schema / properties / chart1 / description

Previous value: -"Birth data for a single natal chart. Required: date (YYYY-MM-DD), time (HH:mm:ss), latitude and longitude in decimal degrees. The short forms lat, lon, lng and tz are rejected with 400 INVALID_FIELD; pass the full names. timezoneOffset is hours from UTC and defaults to 0, meaning UTC; send timezone instead (an IANA name such as Europe/Kyiv, or auto) and the offset for that date is worked out, summer time included. city is a display label only: nothing here geocodes it, so it never stands in for coordinates. houseSystem is a single Swiss Ephemeris letter, P by default; a name such as \"Placidus\" is refused, and the case matters because I and i are two different Sunshine systems."New value: +"Birth data for a single natal chart. Required: date (YYYY-MM-DD), time (HH:mm:ss), latitude and longitude in decimal degrees. The short forms lat, lon, lng and tz are rejected with 400 INVALID_FIELD; pass the full names. timezoneOffset is hours from UTC and defaults to 0, meaning UTC; send timezone instead (an IANA name such as Europe/Kyiv, or auto) and the offset for that date is worked out, summer time included. city is a display label only: nothing here geocodes it, so it never stands in for coordinates. houseSystem is a single house-system letter, P by default; a name such as \"Placidus\" is refused, and the case matters because I and i are two different Sunshine systems."

changedInput schema / properties / chart2 / description

Previous value: -"Birth data for a single natal chart. Required: date (YYYY-MM-DD), time (HH:mm:ss), latitude and longitude in decimal degrees. The short forms lat, lon, lng and tz are rejected with 400 INVALID_FIELD; pass the full names. timezoneOffset is hours from UTC and defaults to 0, meaning UTC; send timezone instead (an IANA name such as Europe/Kyiv, or auto) and the offset for that date is worked out, summer time included. city is a display label only: nothing here geocodes it, so it never stands in for coordinates. houseSystem is a single Swiss Ephemeris letter, P by default; a name such as \"Placidus\" is refused, and the case matters because I and i are two different Sunshine systems."New value: +"Birth data for a single natal chart. Required: date (YYYY-MM-DD), time (HH:mm:ss), latitude and longitude in decimal degrees. The short forms lat, lon, lng and tz are rejected with 400 INVALID_FIELD; pass the full names. timezoneOffset is hours from UTC and defaults to 0, meaning UTC; send timezone instead (an IANA name such as Europe/Kyiv, or auto) and the offset for that date is worked out, summer time included. city is a display label only: nothing here geocodes it, so it never stands in for coordinates. houseSystem is a single house-system letter, P by default; a name such as \"Placidus\" is refused, and the case matters because I and i are two different Sunshine systems."

Addedv1.6.0Oct 24, 2026

TDQS

A3.5/5.0

Behavior4/5

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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new information beyond the annotations: the transport (POST /v1/synastry/element-balance), the required inputs, and a cost of 50 credits at Tier 3, which materially affects whether an agent should call it. It stops short of describing failure modes or what happens with mismatched zodiac/ayanamsa settings between the two charts.

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?

The single prose sentence is front-loaded with the actual computation and contains no filler. The bracketed metadata lines (group, endpoint, required, cost) are compact and scannable, though they are boilerplate repeated across the family rather than tool-specific insight.

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?

For a two-input computation with a full output schema, the agent has what it needs to call correctly: required parameters are stated, the response content is described, and the credit cost is disclosed. The remaining gap is relational — no guidance on choosing this over the structurally similar relational element map or the broader synastry tools.

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%, and the nested chart object carries extensive documentation on date/time formats, timezone handling, ayanamsa, and house-system letters, so the schema does the heavy lifting. The description only implies that both chart1 and chart2 are two independent natal charts being compared, adding no syntax or constraint detail beyond that. A baseline 3 is appropriate.

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

Purpose4/5

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

The description names a specific computation: element (fire/earth/air/water) and modality (cardinal/fixed/mutable) tallies for each chart and the combined pair, plus dominant and missing elements. That is a concrete verb+resource with a clearly bounded output scope. It does not, however, distinguish itself from closely named siblings such as astroway_psychological_modern_arroyo_relational_element_map or astroway_bazi_element_balance, which an agent would need help telling apart.

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

Usage Guidelines2/5

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

There is no explicit when-to-use or when-not-to-use guidance and no named alternative. The word 'synastry' and the phrase 'each chart and the combined pair' imply a two-chart comparison, so usage is inferable, but the '[Group: Comparisons]' tag and sibling list do nothing to route an agent between this and the other relational element tools.

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

Deploy Server