Lunar Calendar

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety needs no restatement. The description adds context annotations cannot carry: the exact endpoint, the required inputs, and a cost of 100 credits at Tier 4, which is a material trait for an agent deciding whether to spend the call.

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?

One front-loaded sentence gives the output contents, followed by a compact metadata block with group, endpoint, required params and cost. Every line carries information; the bracketed block is slightly boilerplate but short enough not to dilute the purpose statement.

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 described, and timezone/day-boundary semantics live in the parameter schema. Combined with annotations and the stated cost, an agent has what it needs to call this correctly; only month-range/edge-case behavior for the generated calendar is unstated.

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 50%: timezone and timezoneOffset are well documented in the schema, but year and month carry no description there. The description only restates that year and month are required and that scope is one month, adding no meaning about accepted ranges, month numbering or defaults, so it does not compensate for the coverage gap.

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 opens with a specific verb+resource ("Calculate a lunar calendar for a given month") and enumerates exactly what the result contains: Moon sign per day, lunar phases, void-of-course windows, perigee/apogee. That content list implicitly separates it from narrow siblings such as astroway_calendar_moon_phase, astroway_calendar_moon_voc or astroway_calendar_ingresses, though none of those are named.

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?

Usage is only implied: the tool is monthly and aggregate, so an agent can infer it should be preferred over per-event siblings when a whole-month overview is wanted. There is no explicit when-to-use/when-not statement or named alternative, leaving the routing decision to inference.

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