Astro Agents - verifiable planetary timing data and astrology

Gun Milan (Ashtakoota matching)

gun_milan

Read-onlyIdempotent

Vedic astrology kundli matching (horoscope matching, marriage compatibility): 36-point Ashtakoota Gun Milan with all 8 kootas and reasons, plus dosha and Manglik checks. Varna, Vashya, Tara, Yoni, Graha Maitri, Gana, Bhakoot and Nadi scored from both Moons, each with the attributes and rule behind the score, Nadi/Bhakoot dosha flags with commonly cited cancellations, and both partners' Manglik status. Boy = person_a, girl = person_b by convention. Deterministic (JPL DE440, no LLM); every result carries meta.result_sha256. Price $0.25 per call via REST POST https://astro-agent.dev/v1/vedic/gun-milan (x402 or MPP); always paid, never a free call.

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": {
      "person_a": "<person_a>",
      "person_b": "<person_b>"
    },
    "name": "gun_milan"
  }
}

Input Schema

Name	Required	Description
`options`	No	Optional calculation settings; every default is the common Parashari convention.
`person_a`	Yes	Groom / boy (traditional convention).
`person_b`	Yes	Bride / girl.

Output Schema

Name	Required	Description
`meta`	No	Provenance of the result.
`error`	No	x402 offer only: why payment is required.
`result`	No	The calculation result.
`accepts`	No	x402 offer only: the payment options (scheme, network, amount, asset, payTo, ...).
`endpoint`	No	The REST route that computed it, e.g. 'western/natal'.
`resource`	No	x402 offer only: the resource being paid for.
`extensions`	No	x402 offer only: protocol extensions (bazaar).
`x402Version`	No	x402 offer only: protocol version (2).

Schema Changelog

Changes observed during successful MCP inspections.

Changed7 schema fields changedNov 3, 2026

addedOutput schema / anyOf

Added value: +[
+  {
+    "required": [
+      "endpoint",
+      "result",
+      "meta"
+    ]
+  },
+  {
+    "required": [
+      "x402Version",
+      "accepts"
+    ]
+  }
+]

addedOutput schema / properties / accepts

Added value: +{
+  "description": "x402 offer only: the payment options (scheme, network, amount, asset, payTo, ...).",
+  "items": {
+    "type": "object"
+  },
+  "minItems": 1,
+  "type": "array"
+}

addedOutput schema / properties / error

Added value: +{
+  "description": "x402 offer only: why payment is required.",
+  "type": "string"
+}

addedOutput schema / properties / extensions

Added value: +{
+  "description": "x402 offer only: protocol extensions (bazaar).",
+  "type": "object"
+}

addedOutput schema / properties / resource

Added value: +{
+  "description": "x402 offer only: the resource being paid for.",
+  "type": "object"
+}

addedOutput schema / properties / x402Version

Added value: +{
+  "description": "x402 offer only: protocol version (2).",
+  "type": "integer"
+}

removedOutput schema / required

Removed value: -[
-  "endpoint",
-  "result",
-  "meta"
-]

Changed1 schema field changedOct 6, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "endpoint": {
+      "description": "The REST route that computed it, e.g. 'western/natal'.",
+      "type": "string"
+    },
+    "meta": {
+      "description": "Provenance of the result.",
+      "properties": {
+        "astronomy_library": {
+          "description": "Astronomy library and version.",
+          "type": "string"
+        },
+        "compute_ms": {
+          "description": "Computation time in milliseconds.",
+          "type": "number"
+        },
+        "computed_at": {
+          "description": "When it was computed (UTC, ISO 8601).",
+          "type": "string"
+        },
+        "deterministic": {
+          "description": "Always true: same input, same result.",
+          "type": "boolean"
+        },
+        "engine": {
+          "description": "Engine name and version.",
+          "type": "string"
+        },
+        "ephemeris": {
+          "description": "Ephemeris used (NASA/JPL DE440).",
+          "type": "string"
+        },
+        "frame": {
+          "description": "Reference frame of the positions.",
+          "type": "string"
+        },
+        "input_sha256": {
+          "description": "SHA-256 of the canonical input.",
+          "type": "string"
+        },
+        "llm_used": {
+          "description": "Always false: no language model is involved.",
+          "type": "boolean"
+        },
+        "payment": {
+          "description": "How this call was paid: protocol ('free' or 'none'), price and the free calls remaining.",
+          "type": "object"
+        },
+        "reproducibility": {
+          "description": "How to reproduce and check this result.",
+          "type": "string"
+        },
+        "result_sha256": {
+          "description": "SHA-256 of the canonical 'result'; check it with verify_result_hash.",
+          "type": "string"
+        }
+      },
+      "required": [
+        "engine",
+        "deterministic",
+        "llm_used",
+        "input_sha256",
+        "result_sha256"
+      ],
+      "type": "object"
+    },
+    "result": {
+      "description": "The calculation result.",
+      "properties": {
+        "doshas": {
+          "description": "Matching doshas such as Bhakoot dosha, with whether each applies and is cancelled.",
+          "type": "object"
+        },
+        "kootas": {
+          "description": "The eight kootas (varna, vashya, tara, yoni, graha_maitri, gana, bhakoot, nadi), each with points scored, maximum and the reason.",
+          "type": "object"
+        },
+        "manglik": {
+          "description": "Manglik status of each person and whether the pair matches on it.",
+          "type": "object"
+        },
+        "max": {
+          "description": "Maximum possible score (36).",
+          "type": "integer"
+        },
+        "person_a": {
+          "description": "First person: subject and natal Moon (rashi, nakshatra, pada).",
+          "type": "object"
+        },
+        "person_b": {
+          "description": "Second person: subject and natal Moon (rashi, nakshatra, pada).",
+          "type": "object"
+        },
+        "settings": {
+          "description": "Settings applied, plus the Ashtakoota ruleset and convention used.",
+          "type": "object"
+        },
+        "total": {
+          "description": "Total Gun Milan score, out of 'max'.",
+          "type": "number"
+        },
+        "verdict": {
+          "description": "Plain-language reading of the total score.",
+          "type": "string"
+        },
+        "warnings": {
+          "description": "Notes on the input or the calculation (for example an assumed noon for an unknown birth time). Present only when there is something to say.",
+          "type": "array"
+        }
+      },
+      "required": [
+        "settings",
+        "person_a",
+        "person_b",
+        "kootas",
+        "total",
+        "max",
+        "verdict",
+        "doshas",
+        "manglik"
+      ],
+      "type": "object"
+    }
+  },
+  "required": [
+    "endpoint",
+    "result",
+    "meta"
+  ],
+  "type": "object"
+}

Changed3 schema fields changedOct 5, 2026

addedInput schema / properties / options / description

Added value: +"Optional calculation settings; every default is the common Parashari convention."

addedInput schema / properties / options / properties / ayanamsa / description

Added value: +"Sidereal reference (ayanamsa). Default 'lahiri' (Chitrapaksha), the Indian standard."

addedInput schema / properties / options / properties / include_outer_planets / description
```
Added value: +"Also return Uranus, Neptune and Pluto (not used in classical Jyotish)."
```

First observedOct 3, 2026

TDQS

A4.4/5.0

Behavior5/5

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

Annotations already cover read-only/idempotent safety, and the description adds substantial context beyond them: deterministic JPL DE440 computation with no LLM, a result_sha256 in metadata for verification, a concrete price of $0.25 per call, and the explicit warning that it is always paid and never a free call.

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?

One dense but well-ordered block: purpose first, then output scope, then partner convention, then determinism, then price/endpoint. Slightly overloaded with parenthetical aliases, but every clause carries information an agent needs.

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?

For a three-parameter call with a deep nested schema and an output schema, the description supplies what the structured data cannot: determinism guarantees, hash verification path, exact pricing, and endpoint/transport. 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 nested person and options fields are already fully documented; the description only reiterates the boy/girl-to-person_a/person_b convention, which the schema also states. Baseline 3 applies since the schema carries the parameter burden.

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 and resource ('36-point Ashtakoota Gun Milan' horoscope matching), enumerates all eight kootas and the dosha/Manglik checks, which clearly separates it from generic siblings like synastry or kundli.

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

Usage Guidelines4/5

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

The framing 'marriage compatibility' plus the enumerate of outputs makes the use context clear, and 'Boy = person_a, girl = person_b by convention' resolves the assignment ambiguity. It never names when to prefer this over synastry or kundli_full, so no explicit alternative routing.

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

All Astro Agents - verifiable planetary timing data and astrology tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.