Moon Phase

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true. Description adds the calculation source (Meeus Ch.48) and cost, but no additional behavioral traits like rate limits or data freshness. With high annotation coverage, a 3 is appropriate as description reinforces but does not significantly extend transparency.

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?

Description is mostly concise with line breaks and group/cost notes. The example request body is useful but slightly lengthy. Could be more streamlined without losing clarity, but overall it efficiently communicates the tool's purpose and usage.

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?

No output schema, but description lists key output fields (illumination %, age, elongation, waxing/waning, zodiac signs) and mentions calculation method. Input parameters are fully covered by schema and example. Fairly complete for a data retrieval tool, though missing details like timezone handling or return format.

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 100%, so baseline is 3. Description provides an example request body that shows parameter usage, but adds no extra semantic meaning beyond the schema's descriptions. The example is helpful but does not elevate the score.

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?

Description clearly states 'current moon phase at a given moment' with specific outputs like illumination %, age, elongation, zodiac signs. Includes example request body. Slightly reduced from 5 because it does not explicitly differentiate from sibling tools like moon_aspects or lunar_calendar, though the name and output specificity help.

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?

No explicit guidance on when to use this tool versus alternatives like moon_aspects or lunar_return. The group label 'Calendar & Cycles' provides some implicit context, but no when-not-to-use or sibling comparison.

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