BaZi / Korean Saju MCP (Four Pillars)

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

No annotations provided. Description mentions determinism, validation, and no AI, but does not disclose behavior for missing hours, error handling, or required input precision. Hour parameter description is included in schema but not elaborated.

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?

Single sentence, under 25 words, front-loaded with key action. Every word serves a purpose.

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, so description must clarify result structure. It lists output components, aiding understanding. However, it does not explain how optional hour (-1) is handled or provide ranges for day and month. Adequate but not thorough.

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 coverage is 40% (2 of 5 params described). Description adds no additional detail beyond schema for required parameters (day, month, gender). For a low-coverage schema, description should compensate, but it does not.

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?

Explicitly states it computes a deterministic BaZi/Saju Four Pillars chart from a solar birth date, listing output components (Heavenly Stems, Earthly Branches, etc.) and noting KASI-validation and no AI. Distinct from sibling 'bazi_compatibility'.

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 vs. alternatives. Sibling tool name 'bazi_compatibility' implies this is for single charts, but no when-not-to or prerequisites stated.

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

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

No annotations are provided, so the description carries the full burden. It states the tool is 'deterministic' and describes the input and output, which implies no side effects. However, it does not explicitly disclose whether it is read-only, requires authentication, or has any rate limits or destructive potential. The description is adequate but not comprehensive.

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 a single, well-structured sentence that front-loads the key information: deterministic nature, output range, and method. Every word contributes meaning, and there is no redundant or extraneous content.

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?

The tool has nested objects, no output schema, and a sibling tool. The description mentions a 'band' but does not define it, nor does it describe the output format in sufficient detail. Additionally, it does not compare with 'bazi_chart' or provide usage context. While it covers the basic purpose, it leaves gaps for the agent regarding output interpretation and tool selection.

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?

The input schema has 100% coverage with descriptions for both parameters ('person_a' and 'person_b'), so the schema already documents the parameter structure. The description adds context that these represent two people and that the output is a compatibility score and band, but it does not elaborate on the nested fields (year, month, day, hour, gender) beyond the schema. The marginal value is moderate.

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 specifies the tool's purpose: computing a BaZi compatibility score and band between two people. It mentions the deterministic nature, score range (0–100), and the underlying methodology (five-element balance and Day Master cycle relation). This distinguishes it from the sibling tool 'bazi_chart', which likely generates a chart rather than a compatibility score.

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 no guidance on when to use this tool versus the sibling 'bazi_chart' or any alternatives. It does not specify prerequisites, context, or exclusions. The agent must infer usage from the tool's name and description alone, lacking explicit decision criteria.

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