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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description's one genuinely additive piece of behavior is the billing disclosure ("5 credits (Tier ½)"), which is not in the schema or annotations; beyond that it says nothing about inputs required or what the palace analysis contains.

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?

Extremely short and front-loaded, with the topic first and the group/cost metadata clearly tagged afterwards. It is efficient, though the brevity borders on under-specification rather than tight editing.

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?

For a 6-parameter chart-derived tool, the description omits how it relates to the Zi Wei chart tools, that birth date (and optionally time) is required, and how it differs from overlapping wellness/medical tools. Having an output schema covers return-value documentation, but the invocation context is still thin.

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 explains none of the six parameters. It gives no hint that a birth date (required), optional time, timezone handling, or the compact-mode `fields`/`precision` options exist, leaving the half-documented `date`/`time` params entirely to the schema patterns.

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 fragment "Body, illness, weak points" conveys the topical domain (the Zi Wei Dou Shu Health palace) but never states a verb or what the tool returns. The name/title already carry most of the disambiguation against siblings like astroway_ziwei_palace_career, so the description adds only a topical gloss rather than a clear purpose statement.

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 is given. An agent cannot tell from the text whether this is a full chart, a sub-analysis, or where it sits relative to astroway_ziwei_chart, astroway_ziwei_full_chart, or astroway_wellness_medical_astrology.

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