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

With no annotations provided, the description carries the full burden and does it well: deterministic rules engine (same day → same answer), public/local access with no API key, timezone of the term-boundary times (Asia/Shanghai), and the exact shape of the payload (24-term table + next upcoming term). Little behavioral ambiguity remains.

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-loads the purpose, then triggers, then return shape — a sensible order. The bilingual trigger list is long and the 'deterministic rules engine' phrasing is slightly meta, but every element is functional and nothing is wasted.

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 zero-required-parameter lookup with no output schema, the description fully specifies the return contents (civil date, exact term-boundary time, next term) and the year coverage, so an agent needs no further information to call and interpret it.

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 100%, so year range (1900–2100) and locale enum are already documented in the schema. The description restates the year range but adds nothing about the locale parameter or formatting behavior, so the baseline of 3 applies.

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?

States a specific verb (looks up) and resource (24-term solar-term table) with explicit scope: full table for any year 1900–2100 plus the next upcoming term. An agent can immediately tell this answers solar-term/jieqi date questions, which no sibling tool name suggests it handles.

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?

Provides explicit trigger conditions in both Chinese and English ('二十四节气 / 今年节气表 / 白露是哪天 / 立春哪天 / next solar term / jieqi'), so the agent knows exactly which user utterances select this tool. It also sets a negative boundary ('Do not invent pillars or fortune claims'), separating it from speculative/predictive tools.

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