Western Moon Calendar

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

Annotations provide readOnly, openWorld, idempotent, and destructive hints, so the description's omission of these details is acceptable. The description mentions defaulting behavior and validation of month range, which adds transparency. No contradictions with 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 description is structured with clear INPUT CONTRACT and WORKFLOW sections, is not overly verbose, and fronts the purpose. The repetition of 'Defaults' and 'DO NOT CONFUSE WITH' mirrors the schema descriptions but is acceptable. Slightly redundant with the schema but not bloated.

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?

Given the tool has a full output schema and sibling context is provided, the description is complete enough. It clearly distinguishes from the single-day sibling and covers validation. The mention of the full output contract link adds completeness, though no detailed output fields are described in the description itself.

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 descriptions cover 100% of parameters with clear defaults and examples. The description itself does not add extra meaning beyond the schema, but the schema is already comprehensive. The response_format parameter is well described with enum values.

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 clearly states the tool returns lunar phase data for every day in a month as a structured array, distinguishing it from the single-day sibling. The verb 'Returns' is specific, but it does not explicitly mention the output format for the array (e.g., JSON structure) beyond referencing the single-day object.

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 description includes a WORKFLOW section stating standalone and no after steps, and a DO NOT CONFUSE WITH section naming the alternative single-day tool. However, it does not explicitly say when to prefer this over the sibling or mention any prerequisites or typical use cases.

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