Tong Shu day: officer and mansion

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered; the description adds the cost (10 credits, Tier 1) and endpoint, which annotations do not carry. It does not say whether supplying a time or timezone changes the answer, nor how the day is bounded (local midnight vs true solar time), which matters for an almanac tool.

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?

One front-loaded sentence naming the reading and its output parts, followed by a compact bracketed metadata block (group, endpoint, required, cost). No filler, though the parenthetical Chinese term and the field list make the sentence dense.

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?

An output schema exists, so return structure need not be explained, and the read-only profile is handled by annotations. What is missing for correct invocation is how time/timezone/language affect the result and how this differs from tong_shu_select — for a paid, day-scoped tool that is a meaningful gap.

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 40% (timezone and timezoneOffset are richly documented, date/time/language are bare). The description only signals that a single date drives the reading; it adds nothing about the date format, the role of optional time, or what language selects. Baseline-adjacent, with a real gap around the undocumented date/time parameters.

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-resource ('The almanac reading of one day') and then enumerates the returned components: day pillar, day officer (建除十二神) with endorsed/forbidden activities, the 28 mansion with quadrant and planet, and the clash animal. An agent can tell this is a single-day Tong Shu lookup, though it never names the nearest sibling astroway_chinese_tong_shu_select to draw the line explicitly.

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?

Usage is implied by 'of one day' and the 'Required: date' line, but there is no statement of when to pick this over the sibling tong_shu_select (which presumably searches/selects dates by activity) or other Chinese calendar tools. No exclusions or prerequisites are given.

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