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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds cost context (5 credits, Tier ½) and the system group, which is useful metadata beyond annotations, but it says nothing about return format, permissions, or rate limits beyond the credit cost.

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 short and front-loaded, and the group/cost metadata lines are structured and useful. However, the core content is a sparse keyword fragment rather than a purposeful statement, so it is under-specified rather than truly concise.

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, but the description still omits what the Children Palace analysis contains, how it differs from related palace tools, and any usage context. For a 6-parameter chart tool in a crowded Zi Wei toolset, this leaves an agent with too little to select and invoke it confidently.

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 provides no information about any of the 6 parameters. Schema description coverage is 67%, with the date and time parameters having only patterns and no textual descriptions, so the description should compensate but does not. The timezone, precision, timezoneOffset, and fields parameters are well documented in the schema, but the description adds zero semantic value on top.

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 is a keyword list ('Children, fertility, juniors') that names the domain but never states a verb or that it returns the Children Palace analysis. It is more informative than the bare title 'Children Palace (Zinu)' because it adds fertility and juniors, but it does not clearly differentiate from sibling palace tools like astroway_ziwei_palace_siblings, where 'juniors' could cause confusion.

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?

There is no guidance on when to use this tool versus the many other Zi Wei palace tools (career, spouse, siblings, etc.) or versus astroway_ziwei_chart / astroway_ziwei_full_chart. The group tag only categorizes the tool; it does not state selection conditions or exclusions.

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