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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered elsewhere. The description adds the required parameter and the cost (5 credits, Tier ½), which is genuine operational context. It does not explain determinism, timezone sensitivity, or what the palace output represents beyond the one-line gloss.

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 content is front-loaded: the thematic one-liner comes first, followed by compact bracketed metadata. There is no filler prose. The bracketed block is slightly noisy but each field (group, endpoint, required, cost) is operationally useful.

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-value explanation is not needed, and annotations cover safety. For a read-only single-parameter calculation the description is minimally adequate, but it omits what distinguishes the Ming palace from its eleven sibling palaces and does not mention timezone sensitivity for birth-time accuracy.

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 coverage is 67%, so the schema documents most parameters (date pattern, time, fields, timezone, timezoneOffset, precision). The description only repeats that 'date' is required, adding no syntax, format, or interpretation guidance beyond the schema. Baseline 3 is appropriate given the schema carries the parameter burden.

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 states a specific subject area: 'Life path, character, soul mission', which is the Ming (Destiny) palace content in Zi Wei Dou Shu. The tool name and title identify the resource clearly, and the sibling set (palace_career, palace_wealth, palace_spouse, etc.) makes the Ming palace's domain distinguishable. It stops short of a full verb+resource statement like 'Computes the Destiny palace placement', so it is clear but not maximally specific.

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 guidance is given. The agent cannot tell from the description whether this requires a birth date versus a chart id, or when to prefer this over astroway_ziwei_full_chart or astroway_ziwei_twelve_palaces. The metadata lines (group, endpoint, required, cost) are operational, not selection guidance.

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