Qi Zheng Si Yu Chart

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

The readOnlyHint annotation already tells the agent that this is a safe, non-mutating computation, and the description is consistent with that. Beyond the annotations, the description usefully discloses the accuracy level (低精度, low precision) and the fact that research-oriented 口径 such as the Guolao life-palace and floating-rise systems are excluded from the core chart. It says nothing about what the returned chart contains, how errors are surfaced, or how any defaulting works.

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?

It is a single dense sentence that front-loads the action and the resource, and every clause carries information (core vs research 口径, input groups, low precision). It leans on domain jargon but contains no filler, and the semicolon cleanly separates the scope statement from the non-mixing rule.

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 19-parameter calculation tool with no output schema and very low schema description coverage, the description covers the required input groups and one critical modeling constraint, but it leaves out what the resulting chart exposes and how the optional descriptive fields are used. It is adequate to invoke correctly, but not complete for interpreting results.

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 only 5% across 19 parameters, so the schema alone leaves most fields unexplained. The description partly compensates by grouping the input requirements into birth moment, timezone, coordinates and explicit palace system, which mirrors the schema's anyOf groups, and by clarifying that palace_system is a 口径 choice rather than a free parameter. Helper fields such as name, locale, question, focus_area, birth_place and is_leap_month stay undocumented in both places.

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 a specific verb and a specific resource: computing the Qi Zheng Si Yu low-precision astronomical core chart (七政四余低精度天文核心盘). That is distinctive enough that an agent can tell it apart from astrology.calculate_chart, bazi.calculate_chart, vedic.calculate_chart and ziwei.calculate_chart, but it does not explicitly name or exclude those siblings.

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?

It states one meaningful usage constraint: the two palace systems (Guolao sun-hour-branch and floating-ascendant equal-house) exist as separate 口径, and they must not be mixed. That implies that the caller must choose palace_system explicitly. It gives no guidance, however, on when to choose this tool over the other chart-calculation siblings, and no prerequisite guidance.

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