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

With no annotations, the description carries the full burden, and it does disclose two genuinely useful operational facts: the tool is paid ($0.05/call) and requires an API key. It says nothing about latency, error behavior, or what happens for invalid input, so it is only partially complete for a mutation-free but billable call.

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?

A single dense sentence front-loads the purpose and appends the cost/auth caveat in parentheses. Nothing is wasted, though the component list is packed and the billing note is easy to miss.

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?

An output schema exists, so return values need not be explained, and the description covers purpose plus cost/auth. It is still incomplete on sibling routing and on any parameter-level guidance, which is the main gap for an agent choosing among five related tools.

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 description mentions no parameters at all. Reported schema description coverage is 0% at the top level (the single 'birth' property is undocumented), so the description does not compensate for the gap; field-level docs exist only inside the nested AgentBirth def.

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?

Names a specific resource (사주 명식) and enumerates the exact outputs it produces — four pillars, ten gods, 12 stages, jijanggan, gongmang, shensha, relations, daeun. That scope distinguishes it from the narrower sibling day_pillar, though it never explicitly names a sibling.

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 when-to-use, when-not-to-use, or alternative routing is given. The agent must infer from the name alone that this is the full-chart tool and that compatibility/day_pillar/monthly/unse are separate concerns.

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