Calendar Round

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely new operational context: the endpoint, that exactly one parameter is required, and a cost of 10 credits at Tier 1. It also explains the semantics of the result (label repeats over the 52-year cycle), which goes beyond annotations.

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

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

The core definition is a single front-loaded clause, followed by compact bracketed metadata. Nothing is padded, though the '[Required: date]' line is redundant with the schema and does not earn its place.

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

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 described, and annotations cover safety. However, for a one-parameter astronomical/calendar tool the description never states what date basis the input uses (Gregorian civil date, timezone, local vs UTC) or how it relates to the sibling Mayan tools, leaving real ambiguity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description carries the full burden for the single 'date' parameter. '[Required: date]' merely restates the schema's required list and adds no format, calendar-system, or timezone guidance beyond the regex pattern's YYYY-MM-DD shape.

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

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

The description states a specific computation: the Calendar Round, defined as combined Tzolkin + Haab producing a unique date label in the 52-year / 18,980-day cycle. This clearly separates it from astroway_mayan_tzolkin and astroway_mayan_haab, which compute only one component each. It does not distinguish itself from astroway_mayan_full, which likely includes this same output.

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

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

The 'combined' framing implies this is the tool to use when both components are needed, but there is no explicit when-to-use guidance or named alternative against the large Mayan sibling set (tzolkin, haab, long_count, full, dreamspell, lord_of_night). Usage must be inferred.

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