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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered without the description. The description does add genuinely useful operational context — the endpoint, the required parameter, and a 10-credit Tier 1 cost — but says nothing about what the response contains or any limitations.

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 definition is short and front-loads the conceptual explanation, with metadata cleanly bracketed below. Nothing is padded, though the first sentence is definitional rather than action-oriented.

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?

With an output schema present, return values need not be explained, and annotations cover the safety profile. However, for a domain-specific esoteric tool surrounded by many similar Mayan siblings, the description leaves the agent without a clear statement of what result it produces or why to pick it.

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 67%, and the two descriptive parameters (fields, precision) are documented in the schema itself. The description's only parameter-related content is 'Required: date,' which merely restates what the schema already marks as required, adding no semantic meaning.

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 defines the subject matter — a '9-day cycle of underworld deities (G1-G9) governing the spiritual influence of each night' — which tells the agent the domain, but it never states a verb or what the tool actually computes/returns for a given date. It reads more like an encyclopedia entry than an action statement, and it does not distinguish this from siblings like astroway_mayan_tzolkin or astroway_mayan_haab beyond the label.

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?

There is no when-to-use guidance, no conditions, and no mention of alternatives among the many Mayan siblings. The bracketed metadata gives 'Required: date' and cost, which is contextual but not usage guidance for selecting this tool over another.

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