Lunar Calendar MCP Server

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

With no annotations provided, the description carries full burden. It discloses the tool's purpose and return format (compatibility score, detailed analysis, recommendations), but doesn't mention error handling, rate limits, authentication needs, or whether this is a read-only operation versus something that might store data.

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 efficiently structured in three sentences: purpose, usage context, and return values. Every sentence adds value without redundancy, and the most important information (what the tool does) comes first.

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?

For a tool with no annotations and no output schema, the description does well by explaining both the purpose and what it returns. However, it could be more complete by mentioning the cultural default (Chinese) and potential limitations or assumptions of the compatibility analysis.

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 the schema already documents all parameters. The description doesn't add any parameter-specific information beyond what's in the schema, but it does provide context about how the parameters relate to the analysis (dates used for zodiac/element compatibility).

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 specific action ('Analyzes compatibility'), resource ('between two dates based on their Chinese zodiac animals and five elements'), and distinguishes from siblings by focusing on pairwise date compatibility rather than batch processing, bazi calculation, or other date-related functions.

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 provides clear context for when to use this tool ('traditionally used for checking compatibility between birth dates for relationships, partnerships, or selecting compatible dates for joint ventures'), but doesn't explicitly state when NOT to use it or name specific alternatives among the sibling tools.

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