Astro Agents - deterministic Western + Vedic astrology

Kundli (Vedic birth chart)

kundli

Read-onlyIdempotent

Vedic astrology birth chart (kundli, Jyotish horoscope, D1 and D9): lagna and the nine grahas with rashi, nakshatra, pada, house, dignity and combustion. The Jyotish birth chart: ayanamsa (Lahiri default; Raman, KP, Yukteshwar, Fagan-Bradley, True Chitrapaksha), lagna, grahas with rashi, nakshatra/pada/lord, bhava, dignity (exalted, debilitated, moolatrikona, own sign), retrograde and combustion, house table with lords and occupants, and the Navamsa (D9). Deterministic (JPL DE440, no LLM); every result carries meta.result_sha256. Price $0.15 per call via REST POST https://astro-agent.dev/v1/vedic/kundli (x402 or MPP); your first 3 calls are free here.

Input Schema

Name	Required	Description	Default
`date`	No	YYYY-MM-DD (use with 'time' instead of 'datetime').
`time`	No	HH:MM or HH:MM:SS, 24 h. Omit if unknown (computed at 12:00 with a TIME_UNKNOWN warning).
`options`	No	Optional calculation settings; every default is the common Parashari convention.
`datetime`	No	Local birth date-time, ISO 8601: '1990-05-15T14:30' (local clock time at the place) or with an explicit offset '1990-05-15T14:30:00+02:00'. Alternative: 'date' + 'time'.
`latitude`	Yes	Decimal degrees, north positive.
`timezone`	No	IANA zone, e.g. 'Asia/Kolkata'. Optional: resolved from the coordinates, with the historical offset (DST, Local Mean Time) of that date.
`longitude`	Yes	Decimal degrees, east positive.
`time_basis`	No	What the given clock time is: civil wall-clock (default), UTC, Local Mean Time, or true (apparent) solar time.	civil
`ambiguous_time`	No	Which occurrence to use when a local time happens twice (DST fall-back).	earlier

Output Schema

Name	Required	Description
`meta`	Yes	Provenance of the result.
`result`	Yes	The calculation result.
`endpoint`	Yes	The REST route that computed it, e.g. 'western/natal'.

Schema Changelog

Changes observed during successful MCP inspections.

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": {
+        "bhavas": {
+          "description": "The twelve houses (bhavas): sign, rashi, lord and the grahas occupying each one.",
+          "type": "array"
+        },
+        "grahas": {
+          "description": "The nine grahas (Sun to Ketu): sidereal longitude, rashi, sign lord, nakshatra, pada, nakshatra lord, deity, house, and dignity flags.",
+          "type": "array"
+        },
+        "lagna": {
+          "description": "The ascendant (lagna): sidereal longitude, rashi and sign, degree, sign lord, nakshatra, pada and nakshatra lord.",
+          "type": "object"
+        },
+        "settings": {
+          "description": "Settings applied: sidereal zodiac, ayanamsa (name and value in degrees), lunar node type, house system and divisional-chart rules.",
+          "type": "object"
+        },
+        "subject": {
+          "description": "The resolved input: 'time' (local input, time zone and historical UTC offset, UT, Julian days, Delta T) and, when given, 'location' (latitude, longitude).",
+          "type": "object"
+        },
+        "summary": {
+          "description": "Key facts: lagna sign and lord, Moon sign, sidereal Sun sign, janma nakshatra with pada and lord, and the exalted, debilitated, retrograde and combust grahas.",
+          "type": "object"
+        },
+        "vargas": {
+          "description": "Divisional charts D1 (rashi) and D9 (navamsa), keyed by name.",
+          "type": "object"
+        },
+        "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": [
+        "subject",
+        "settings",
+        "lagna",
+        "grahas",
+        "bhavas",
+        "summary",
+        "vargas"
+      ],
+      "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

B3.3/5.0

Behavior4/5

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuine value beyond them: deterministic computation (JPL DE440, no LLM), a per-result integrity hash (meta.result_sha256), a $0.15 per-call price, and the REST endpoint with x402/MPP payment. It stops short of describing failure modes (e.g. what happens on out-of-range coordinates or ambiguous dates) or rate limits.

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

Conciseness3/5

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

Front-loaded with the core purpose, which is good, but the middle is repetitive: the chart contents (lagna, grahas, rashi, nakshatra/pada, dignity) are listed twice in near-identical phrasing. Large chunks of the text describe return values that an existing output schema already covers, so several sentences do not fully earn their place.

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

Completeness3/5

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

With a full output schema, the extensive enumeration of returned fields is unnecessary, while the genuinely useful missing piece — how this differs from kundli_full — is absent. A 9-parameter tool at 100% schema coverage leaves the description only moderate work to do, and it does not do the routing part of it.

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 every parameter, enum and default is already documented in the schema, so the description need not carry this burden. The ayanamsa list in the prose is largely redundant with the schema enum, though it does mildly reinforce that Lahiri is the default convention.

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?

States a specific verb+resource (compute a Vedic birth chart / kundli) and enumerates the artifacts (lagna, nine grahas, rashi, nakshatra, pada, house, dignity, combustion, navamsa). However, it never distinguishes itself from the near-identically named sibling 'kundli_full', nor from natal_chart or vedic_report, so an agent cannot route between them from this text alone.

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?

No when-to-use or when-not-to-use guidance is given. With 16 siblings including kundli_full, natal_chart, vedic_report and panchang, the absence of any routing rule is a real gap. Commercial details (price, first 3 free) are present but that is not usage guidance.

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

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