bazi_cast

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 adds meaningful behavioral guardrails: the host MUST NOT invent pillars, stems, branches, or wuxing, and it discloses the lunar-python dependency. It does not describe the failure mode if the dependency is missing, but this is still strong behavioral disclosure for a computation-heavy tool.

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 two sentences with no filler: it front-loads the core action and resource, then states the critical operational constraints. Every sentence earns its place, and the result is compact without sacrificing important detail.

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 presence of an output schema and fully covered parameters, the description adequately covers the human-guardrail and dependency context. It could go further by addressing edge cases like the Zi-hour day boundary or missing-dependency behavior, but the current combination is sufficient for an agent to invoke the tool correctly in most cases.

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 three parameters. The description adds no parameter-specific meaning beyond what the schema provides, such as the exact-time requirement for the hour pillar and longitude enabling true-solar-time correction. Baseline 3 is appropriate.

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 ('Cast') and names the exact resource ('Bazi (八字 / Four Pillars) chart') plus the required input format ('Gregorian birth datetime'). This clearly differentiates it from sibling tools like tarot_draw, iching_cast, and xiaoliuren_cast, which represent different divination systems.

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?

While the description does not explicitly name sibling alternatives, it establishes a clear trigger scenario: casting a Bazi chart from a Gregorian birth datetime, with exact birth time and optional timezone/longitude prerequisites. The context is clear enough for an agent to know when this tool applies, though explicit 'use X instead' guidance is absent.

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