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

Annotations already declare this a read-only, idempotent, non-destructive, closed-world call, so the safety burden is lifted. The description earns credit by adding context the annotations don't carry: the output is exact instants expressed in both UTC and Beijing time, and it explains the astrological role of the two groups of twelve terms. It says nothing about pagination or volume, but with an output schema present that is largely redundant.

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?

Two dense sentences lead with the resource and scope, followed by compact bracketed metadata for endpoint, required input, and cost. Every line carries signal — no filler, no restated name/title padding.

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 read-only list endpoint with one required parameter, an output schema, and full annotation coverage, the description supplies what an agent needs: what is returned, in which time representations, and why the two halves of the list differ. The remaining gap is the undocumented `language` parameter, which is left to inference.

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 only 50%: `fields` and `precision` are documented in the schema, while `year` and `language` have no schema descriptions. The description confirms `year` is required and that the scope is one solar year, but never clarifies the accepted year range (2–2899) or what `language` controls. It compensates only partially for the coverage gap, so the 3 baseline is appropriate.

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 resource — the 24 solar terms of a Chinese solar year — and specifies the return form (exact instants in UTC and Beijing time). This is distinctly more than a restatement of the title. It stops short of naming any sibling tool (e.g. astroway_chinese_lunar_date or astroway_calendar_ingresses) to draw the boundary, so it lands at clear-but-undifferentiated.

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?

The second sentence implies the domain of use — solar terms matter because twelve open a BaZi pillar month and twelve decide leap months — which hints at when an agent would want this. But it gives no explicit when-to-use, no contrast with alternatives, and no stated preconditions. Usage is inferred, not prescribed.

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