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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds the 10-credit cost and the endpoint, which are genuinely useful behavioral facts, but the rest of the text is domain explanation (calendar structure, Wayeb) rather than tool behavior. With annotations carrying the main burden, this is adequate but not rich.

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 front-loaded in one tight sentence, with metadata tags following. The bracketed tag block (group, endpoint, required, cost) is slightly noisy but each entry carries information an agent can act on, so it earns its space.

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 explained, and this is a simple one-required-parameter tool. The description covers the domain, the cost, and the required input adequately. Minor gaps include any date-range or timezone assumptions for the `date` parameter, but nothing essential is missing.

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%: `fields` and `precision` are well documented in the schema, while `date` carries only a regex pattern. The description's '[Required: date]' merely restates the schema's required array and adds no format or range detail. Baseline 3 is appropriate since the schema does most of the work.

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 names the specific resource (the Haab 365-day civil calendar) and its structure, and states the operation: identifying whether a date falls in the Wayeb period. An agent can distinguish it from sibling Mayan tools like tzolkin, long_count, or lord_of_night by resource. It stops short of an explicit verb+object phrasing such as 'compute the Haab position for a given date,' but the intent is unambiguous.

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 guidance on when to choose this over astroway_mayan_full, astroway_mayan_calendar_round, or the other Mayan calendar siblings. The [Required: date] and [Cost: 10 credits] tags give invocation logistics but no usage context or exclusions.

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