Branch and stem interactions

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered; the description's added value is the [Cost: 10 credits (Tier 1)] note and the endpoint/group metadata, which are genuinely useful for agent budgeting. It adds nothing about output shape, computation caveats, or what happens when optional inputs (time, timezone) are omitted.

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 dense front-loaded sentence followed by a compact structured metadata block; nothing is padded. It is arguably too terse for the parameter surface it exposes, but there is no wasted text.

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 values need not be explained, but a 12-parameter, 17%-documented BaZi tool with several school/boundary switches needs guidance the description does not provide (defaults, which optional inputs matter, how they affect interactions). The definition is incomplete for its complexity.

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 17% across 12 parameters; only timezone and timezoneOffset carry descriptions. The description explains no parameter at all — dayBoundary, includeLuck, stageSchool, trueSolarTime, includeFullTable and longitude are all left for the agent to guess, and the [Required: date] line merely echoes the schema.

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 the specific interaction types returned (stem combinations, six harmonies, full/half trines, clashes, harms, punishments, self-punishments) plus the pillars involved and the produced element, so an agent can tell exactly what data it yields. It is written as a noun phrase rather than a verb+resource statement and never contrasts itself with the many sibling BaZi tools (chart, four_pillars, ten_gods, hidden_stems), so differentiation is left to inference.

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 or when-not-to-use guidance is given, and no alternative is named despite dozens of adjacent BaZi endpoints. The only contextual cue is the [Required: date] line, which restates the schema rather than describing intent.

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