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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description usefully adds the cost (5 credits, Tier 1/2) and the raw endpoint, which an agent cannot get from structured fields, but it says nothing about auth requirements or response shape.

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?

Front-loaded topic keywords followed by a compact metadata block; no sentence is wasted. It is terse to the point of under-specification rather than padded.

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?

With an output schema present, return values need no explanation, and annotations cover safety. Still missing is any differentiation from the broader ziwei chart tools and any statement of what the Children-palace response actually contains, which leaves selection ambiguous among many similarly named siblings.

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 67% and the description contributes no parameter meaning beyond restating that date is required. Rules for baseline 3 (>80% coverage) are not met, but most parameters (fields, precision, timezone, timezoneOffset) are self-documented in the schema and time is pattern-constrained, so the gap is modest.

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 names the resource domain ('Children, fertility, juniors') and the group tag identifies it as a Zi Wei Dou Shu palace computation, which lets an agent tell it apart from astroway_ziwei_palace_siblings or astroway_ziwei_palace_spouse. However there is no verb (compute/derive) and the resource is implied through a keyword list rather than stated, so clarity comes mostly from the name and title.

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 when-to-use guidance at all: nothing says how this differs from astroway_ziwei_chart, astroway_ziwei_twelve_palaces, or astroway_ziwei_full_chart, nor when a single-palace call is preferable to the full chart. '[Required: date]' is a prerequisite but merely restates the schema.

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