Moon Phase Software

Eclipses of a year

list_eclipses

Read-onlyIdempotent

Returns the lunar and solar eclipses of a calendar year with their type, the time of greatest eclipse in a time zone, the contact times of lunar eclipses, where solar eclipses are greatest and which of 16 major world cities see each one. The type filter limits the list to lunar or solar eclipses.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_eclipses"
  }
}

Input Schema

Name	Required	Description
`type`	No	Limits the list to lunar or to solar eclipses; both when omitted.
`year`	No	Calendar year from 1900 to 2100; the current year when omitted.
`timeZone`	No	IANA time zone name such as America/New_York or Asia/Tokyo; UTC when omitted.

Output Schema

Name	Required	Description	Default
`view`	Yes
`items`	Yes
`total`	Yes
`request`	Yes
`pageSize`	Yes
`nextCursor`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedNov 11, 2026

TDQS

A3.7/5.0

Behavior4/5

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

Annotations already declare read-only, idempotent, closed-world, and non-destructive behavior, so safety needs no restating. The description adds genuinely useful behavioral context by spelling out the exact contents of the result — contact times for lunar events, greatest-eclipse coordinates for solar ones, and the 16-city visibility breakdown — which tells the agent what it will actually receive. It does not mention performance, caching, or result size, which keeps it short of a 5.

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?

Two sentences, front-loaded with the resource and its returned fields, no filler or marketing language. The first sentence is dense with a long list of items, which makes it slightly harder to parse but every element it names is substantive, so nothing is wasted.

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 the return-value explanation is bonus depth rather than an obligation, and default behaviors are covered in the schema. Combined with annotations that fully handle the safety profile, the definition gives the agent enough to call this correctly for a simple, three-optional-parameter read tool. Only the lack of any routing guidance against the sibling moon tools leaves a modest gap.

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 defaults (current year, UTC, both eclipse types) and the year range. The description only adds the type-filter sentence, which duplicates schema text and says nothing new about year or timeZone semantics. Baseline 3 is correct because 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?

The description opens with a specific verb and resource ('Returns the lunar and solar eclipses of a calendar year') and then enumerates the exact payload: type, time of greatest eclipse in a time zone, contact times, greatest-eclipse locations, and which of 16 world cities see each one. That level of detail makes the tool's scope unmistakable and clearly distinct from the moon-phase/moonrise siblings.

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?

Nothing in the description says when to reach for this tool over the moon-phase or moonrise/set siblings, nor when not to. The only conditional statement ('The type filter limits the list to lunar or solar eclipses') restates what the schema already says about the type parameter rather than giving usage guidance.

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

All Moon Phase Software tools Inspect

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